Introduction
Heat tolerance is the ability of the human body to work in heat. All people are not the same and it is possible that some individuals develop excessively high levels of hyperthermia (body temperature raise) during work in heat and this may lead to heat disorders and heat stroke, which is life-threatening. The heat tolerance screening process is an assessment to prevent employees that are heat intolerant to perform work at hot areas.
Objective
The primary objective of HTS is to identify gross or inherent heat intolerance individuals with an unacceptable risk to themselves and to the mine.
The nature of the test is also to provide a measure of physical fitness and, therefore, serves as a secondary objective.
Interpretation
Heat tolerant
- Heat tolerant means a person with the absence of any abnormal response during or at the end of the test e.g. collapse, vomiting, headache and lack of co-operation and whose oral temperature does not exceed
- 37.6°C at the end of a test: This implies that a person is fit to undertake physical demanding work in a hot environment.
Heat intolerant
- Individuals with oral temperatures in excess of 37.6°C on completion of the test should be considered to be heat intolerant.
- In the event of a HTS failure the individual must then be re-assessed by the medical staff to identify inherent causes. On advice from the medical practitioner a second test is permissible, but not within a period of two days. Repeated failure of the test means that the candidate would be disqualified from work in hot environments.
Eligibility. Frequency of Screening
Eligibility
- HTS should be seen as one of a number of the criteria determining overall fitness for physically demanding work in hot environments. For this reason, all employees who enter hot environments in the normal execution of their duties must be tested. There will be no distinction between employees exposed to a full shift or those who only enter a hot environment sporadically.
Exception from HTS
- Due to the nature of their work the hoist drivers will not be screened. PROTO members will be exempted from the screening at the mine. Any other exception will only be allowed with the written permission of the General Manager.
Frequency of heat tolerance screening
Annual HTS
- Any employee deemed fit for physical work in hot environments by virtue of the initial test would only be required to undergo HTS once a year on returning from annual leave.
Frequency of heat tolerance screening
Additional HTS
Absenteeism
- The period of absenteeism is immaterial provided that the employee does not fall ill during this period of absence. It will be the responsibility of the employee to submit a copy of the sick note to the Occupational Health centre on returning from absence.
Absenteeism due to illness, especially febrile disease
- It will be mandatory for an employee to do HTS before resuming work in hot environments. A copy of all sick notes must be submitted to the medical station.
Heat related incident
- When an employee reports any form of heat related illness such as heat stroke, heat exhaustion, dizziness, fatigue or cramps, the medical personnel will assess the person and the employee must undergo HTS before resuming work.
HTS outcome.
- Any individual who passes the HTS test can be allocated to work in hot environments without any restriction.
- Individuals who fail the test will be considered unfit to perform work in hot environments.
- New candidates (novices) who fail should be regarded as unfit to perform work underground.
- Where existing employees fail the HTS test the following protocol will be in place.
- A special medical examination should be conducted to determine the underlying cause with the focus on medical history and especially history on heat disorders. Where recurring heat disorders are evident the person should be declared unfit for work in hot environments.
Placement.
- Where possible the individual should be placed in a working place with temperatures below 27.5°C wet bulb and ensure that he is restricted to this area.
Strenuous work.
- Where a person is performing work currently and the nature of his work is not strenuous he may continue in that position provided that:
–The individual was counselled on the relevant risks;
–The individual was counselled on the factors which increase the risk of contracting heat disorders e.g. the use of alcohol, bad eating habits and low intake of water and he accepts that any occurrence of heat disorders may render him unfit for that position;
–That the medical practitioner agreed with the decision;
–That the temperature does not exceed 32.5°C wet bulb.
–That the direct supervisor formally accepted instructions concerning safe work practices.
Safe work practices
Natural acclimatization
- The successful pass of the HTS does not mean a person is acclimatised to perform work in hot environments. Such a person must still undergo a period of exposure to allow the body to adapt to perform work in a hot environment. The degree of acclimatisation ultimately achieved is a function of metabolic work rate, the environmental heat load, exposure time and the repetition of the exposure. Natural acclimatisation is done in a working place where temperatures are conducive to heat disorders. During this period the risk of contracting heat disorders is high and the following protocol for natural acclimatisation is prescribed.
Exemption from Natural Acclimatization.
- Employees who only enter hot environments sporadically, by virtue of their occupation will be exempted from natural acclimatization, these employees should know the symptoms and treatment of heat related disorders, but need not undergo a period of natural acclimatization:
–Management team Mine Overseers Mine Safety Officers
–HR Department employees
–Engineer
–GES
–Engineering Foremen
–Service department personnel (Survey, Sampling, Environmental Control, Geology) Security Department
–Full Time Health & Safety Representatives a)
Formal supervision.
- The fact that a person is heat tolerant is not a guarantee against the possibility of developing heat disorders, including heat stroke, if the basic precautions are not observed. It will be the responsibility of the line supervisor to ensure that these precautions are followed, especially the period of Natural Acclimatisation.
SUPERVISION AND DUTIES
Training Centre
Induction training
- The training department is to ensure that all employees receive the relevant training in the risk of heat when working in hot environments.
- The training must include the following:
–The risk of heat stroke, heat exhaustion and other heat related illnesses.
–How to prevent or reduce the risk of contracting heat disorders.
–How to identify symptoms of heat disorders?
–How to treat a person who has contracted heat disorders?
–The right to withdraw when a working place are above the legal limits.
–The risk of contracting heat related disorders may also at occur at temperatures below 32.5Wb
Annual refreshment training
- Each employee must receive refresher training relevant to his occupation and to heat related exposure at least once a year. A record of training is to be kept.
- The training department is to train the Shift bosses, miners in the use and maintenance of their whirling hygrometers.
HR Department
- The staff in the HR department is to receive full training in the practical application of this code of practice with special regard to procedures to be followed with personnel transfers between sections and mines and from one occupation to another. A member of the personnel department staff is to accompany the employee and introduce him to the relevant head ofdepartment (HOD) on the day before he proceeds underground. He must ensure that the HOD is fully aware of the fact that the employee is to undergo the period of natural acclimatization. The HOD is to sign an appointment (copy attached) for each such employee as an indication of acknowledgement and acceptance of responsibility. The signed appointment is to be filed with the personal record of the employee. A copy is to be given to the HOD for his records.
- The personal records of all employees are to be kept up to date with the results of HTST and the period of natural acclimatization.
Underground supervisory personnel
- All underground supervisory personnel are to be fully trained before proceeding underground after engagement and at least once a year thereafter in the requirements of this code of practice.
All underground employees
- All underground employees are to be fully trained before proceeding underground after engagement and at least once a year thereafter in the dangers of heat, the symptoms and treatment of heat disorders.
Placements
- The HR department is to ensure that employees who are found heat intolerant are not placed in working places with temperatures above 27.5 oc Wb.
Transfers
- When employees are transferred from a cool environment (<27.5 WB) to hot environments the Line Supervisor is to ensure that the person undergoes 12 shifts of natural acclimatisation in his/her new environment.
Absenteeism
- Absenteeism associated with any form of vacation leave other than his/her annual leave, such as the attendance of conferences, training courses and other prolonged absenteeism etc.
- The employee will report to the Occupational Medical Centre where a basic assessment will be conducted and if declared fit by the Occupational nurse the employee may proceed and resumes normal work without doing HTS. It will be the responsibility of the direct supervisor to ensure that the 12 shift natural acclimatisation is done.
- On returning from annual leave, the employees must undergo the annual routine medical physical examination and HTS.
Absent due to illness/ accidents:
- All Employees and contractors returning from absence because of illness must report to the
- Occupational Health Centre before resuming work underground.
- A close liaison is to be maintained with the medical department regarding the medical condition and history of the workers to ensure they undergo the HTST whenever necessary.
Duties for Natural Acclimatization
HTST and Natural Acclimatization procedures as prescribed in the COMRO publication “HEAT STRESS MANAGEMENT – A COMPREHENSIVE GUIDE” are to be strictly adhered to with special regard to the following:
Identification
- Natural Acclimatization Attendance record form is to be issued to these employees for the period of natural acclimatization. The form is to be signed at the end of each shift by the line supervisor. (Copy attached). On completion the record form is to be send to the Occupational Health Centre for filing with the employee’s personal records.
Environmental Conditions
- The wet bulb temperature in the working places where natural acclimatization is done must be higher or equal to 27.5°C Wb with a maximum of 32,5°C Wb. No person is to be allowed to perform work where the wet bulb temperature is in excess of 32,5 oc Wb or a dry bulb temperature in excess of 37,0 oc Db during the process of natural acclimatization.
3Shift times
- Natural acclimatization is to be done in the normal working conditions these employees are to spend the full shift in their normal working place. No employee is to be allowed to work on any other shift prior to completion of the 12 shifts of natural acclimatization.
Special Precautions
- Hourly water breaks are mandatory during which a minimum of 2 x 250ml of any acceptable fluid replacement (preferably water or hypo tonic beverages only) should be taken.
- No deviations from a recognised job description should be permitted.
- Regular checks for symptoms of imminent heat disorders should be conducted at least during the water breaks; appropriate action should not be delayed.
- Whereas the above precautions are applicable to all workers undergoing natural acclimatization, close supervision is necessary where work is regarded as “hard” or “strenuous”. Water should be taken more frequently e.g. every 20 or 30 minutes while conducting the above checks.
Absenteeism (during 12 shift period of natural acclimatization)
- Workers absent during the 12 shift period of natural acclimatization for more than two shifts due to illness or any legitimate reason and for any period without leave (AWOP), are to redo HTST and the full period of natural acclimatization
RESPONSIBILITIES
- It is the responsibility of all persons in supervisory positions to ensure that all the requirements of this code of practice and the COMRO publication “HEAT STRESS MANAGEMENT – A COMPREHENSIVE GUIDE” are met.
- All incidences of deviation from the requirements are to be rectified immediately and fully investigated to enable a re-occurrence to be prevented.
General Manager and Manager Mining
- The manager to give written permission to allow exceptions to persons performing work underground who are not heat tolerant. The manager to ensure that the procedure in point 3.4.3.of the HSMP is adhered to.
Mine Overseer
- The mine overseer is overall responsible to ensure that the Heat Stress Management procedure is successfully implemented. The manager mining is to show his commitment by ensuring that all employees receive appropriate training at the specified intervals. During his underground visits they should do spot checks and demonstrate awareness of the importance of the proper management of the procedure by practical participation.
- The mine overseer is to ensure that all the supervisors in his section are fully conversant with the requirements regarding heat stress management programme.
- He must appoint the responsible line supervisor who will monitor the person undergoing NA of 12 shifts.
- He is to demonstrate his commitment by participation and positive motivation of the employees in his section.
- The Shift Supervisors logbooks are to be scrutinised daily for the required comments relating to the employees undergoing natural acclimatization.
- He is to ensure that drinking water is available at all working places.
- The mine overseer must ensure that when employees are transferred from working places where the temperature is below 27.5 WB to hot working places that the 12 shift Natural Acclimatization is observed.
- On underground visits the Mine Overseer is to do spot checks to ensure that the special precautions relating to natural acclimatization are complied with.
- The mine overseer is to ensure that ventilation appliances and controls are in place and report any change in ventilation system to the environmental department.
- The mine overseer is to ensure that all the Shift Supervisors are issued with a whirling hygrometer and receive the necessary training from the training department.
Shift Supervisors/ foreman
- Whenever an employee, new or transferred from another gang or section, is placed on a gang under the control of a Shift Supervisor, he should ensure that the employee qualifies to work in the section as regards to the thermal environment. He should determine whether the employee is required to undergo a period of natural acclimatization prior to commencing work.
- The Shift Supervisor is to ensure that the ganger/miner, team leaders and gang supervisors concerned are aware of all the employees in the process of natural acclimatization in their area of supervision and he must ensure that they comply with the special precautions prescribed for this process.
- The Shift Supervisor must ensure that the Natural Acclimatisation cards are filled in correctly by the line supervisor and return the record card to the Mine Overseer who will forward it to the Occupational Health clinic on completion of the 12 shifts.
- All Shift Supervisors are to measure the temperature in all the working places his section daily and record environmental conditions in the logbook. When temperatures exceeds 32.5°C wet-bulb work must be stopped.
Shift Supervisors/ foreman
- Any abnormal ventilation occurrences are to be investigated and fixed if the condition prevail it must be reported as soon as possible to the Mine overseer and environmental control department. Such occurrences and actions taken are to be recorded by the Shift Supervisor in his daily logbook.
- The shift Supervisor/foreman must ensure that a copy of all sick notes are send to the Occupational Health
- Centre on the same day of return including sick notes from private doctors.
Ganger/Miner, Line supervisor, Team- and Gang leader
- Miners, Shift supervisors and Snr Team Leaders must be trained in the use of whirling hygrometers.
- The ganger or miner is not to receive any worker who has not completed the HTS test. Any worker who has been absent for more than seven days or any worker who has been ill is to have a clearance letter from the Occupation Health Centre before he is accepted back at work.
- The ganger/miner is to ensure that the team leaders and gang supervisors concerned, are aware of all the employees in the process of natural acclimatization in their area of supervision and he must ensure that they comply with the special precautions prescribed for this process.
- The employee in the process of natural acclimatization must be visited regularly during the shift in the working place by his supervisors to ensure that he complies with the special precautions prescribed for the process.
- The Natural Acclimatization Attendance record form issued to the Mine overseer is to be signed daily by the ganger/miner.
- The ganger/miner must take temperatures and record the results in his notebook.
Ventilation Department
- The ventilation department is to ensure all that the areas on the mine in which the conditions require that employees be acclimatized are to be identified.
- All working places are to be surveyed quarterly and recommendations to improve conditions are to be made where necessary.
- Ensure that the medical department receives the results of environmental conditions.
- Investigate all heat related incidents and I or complaints from the mining department or health and safety representatives.
- Heat related investigations should include the person’s HTS and natural acclimatisation records.
Safety Department
- The Safety Officers and safety representatives are to audit the standard of adherence with the requirements of this Code of Practice during their routine underground visits.
HR Department
- Each week the HR department will supply the Occupational Health department with a list of employees going on leave, with the date on which the employee is expected to return, his occupation and working section.
Employees
- It will be the responsibility of the employee to report to the clinic when he /she is sick.
- It will also be the responsibility of the employee to submit his/her sick note to the HR department and report to the Occupational Health Centre after been absent from work.
- Employees must understand that alcohol abuse and bad eating habits may increase the risk of contracting heat illness.
- Employees must drink water regularly when doing work in hot environments to prevent dehydration.
Occupational Health Centre
The medical department will be responsible for:
- The Medical and Physical examinations as per the COP for fitness to perform work on the mine and medical surveillance according to the risk of exposure.
- The safe keeping of medical records and historical heat related illness of employees.
- Notifying the environmental department of any suspected heat illness.
- Ensuring that the procedures at the climatic centre are followed.
- Ensuring that the hygiene in the climatic chamber is always good.
- Ensure that HTT screening is done on underground employees who return from leave, those who have been absent from their workplace for more than seven days and all who have suffered from febrile disease or heat related illness.
- The OHP must forward the Natural Acclimatisation attendance record form to the Mine overseer as soon as the employees successfully completed HTS.
Contractors
- All contract employees required to perform work in the mine are to comply with this code of practice. It is the responsibility of the Mine Overseer of the mine concerned to enforce this aspect. A codicil to this effect is to be included in all the contract agreements with contractors.
Visitors
- Prior to any visit, the mine employee responsible for arranging/accompanying the visitors will ensure that the visitors sign the Indemnity Form ANNEXURE “A” as prescribed and that they present themselves at the Occupational Health Centre for a short medical examination as prescribed by the Occupational Health Co-Ordinator.
Facilities and Supervision
- HTS should be conducted only in climatic chambers with a satisfactory degree of environmental control and only under the supervision of qualified personnel.
Quality control
- Regular inspection must be carried out by the responsible supervisor to ensure high hygiene standards. Monthly inspections must be done by the Environmental department to audit the accuracy of the temperature control instrumentation.
- A comprehensive annual audit must be carried out with regard to the supervisory proficiency, the facility in its entirety, instrumentation, procedures and reports. This audit should be done by an accredited occupational hygienist.
HTT Chamber Supervisors
- The supervisor should be trained in the procedure in the controlling of the climate in the chamber.
- The supervisor must be trained and find competent in the use of whirling Hygrometers and thermometers by the training department.
- The supervisor must be trained in the calibration check of thermometers. Whenever the temperature increases above the controlled level HTS must stop.
- During the summer season HTS must stop when the ambient temperature makes the climate control difficult.
- He/she must be trained in the recognition of heat exhaustion and heat stroke.
- He/she must be trained in the treatment of heat exhaustion and heat stroke. He/she must be able to read and write to record conditions.
Climatic Chamber Hygiene
- The hot humid conditions are conducive to the proliferation of microorganisms therefore it is imperative that a satisfactory standard of hygiene be maintained in order to protect staff and workers.
Disinfectants
- It is important that a suitable disinfectant agent be used for each of the various applications. No disinfectant solution should be prepared more than 12 hours before use.
Hand washing
- Before entering the climatic chamber all test center personnel should wash their hands thoroughly with disinfectant soap and again after using the toilets. Personnel should also wash their hands before and after every body temperature measurement.
Footbath / foot disinfectant
- On entering and leaving the climatic chamber each worker should properly disinfect both feet.
Thermometers
- After use the thermometers must be washed and then disinfected by total immersion in a container of freshly prepared disinfectant. Used thermometers must be placed in a separate container for washing and sterilization.
- At no time should any thermometer be re-used if not washed and disinfected.
Floors and stepping bench
- Floors should be cleaned and disinfected after every test.
Shower Facilities
- To ensure that employees clean and cool themselves after the completion of the test, they should shower, washing themselves thoroughly with soap and water.
Laundering
- PT shorts or skirts used during tests should be disinfected and laundered prior to re-use. Employees are free to make use of there own PT shorts.
General
- The maintenance of the floors and walls must be done continuously. The risk of slippery floors must also form part of the maintenance of the chamber.
- It is also recommended that sample swabs for microbiological examination should be taken from the floor and stepping bench. This monitoring should be done as an ongoing programme.
General HTS procedure
Pre-test
- All candidates for testing must first complete the medical examination prior to the test. No smoking is allowed and no liquid refreshment should be taken just before the test.
Induction
- The candidates must be informed of the procedure. Workers must also be warned against symptoms of heat illness.
Pre-test
- Armpit temperatures should only be measured with thermometers which have been checked for accuracy. The thermometer must be checked against a certified thermometer at a temperature of 37.0 degrees and 39.0 degrees respectively.
- Comparing a number of thermometer readings at a temperature of 37.0 °C and 39.0 °C respectively can also be used as a means of calibrating. Thermometer failing the test must be discarded.
- Any individual displaying a resting temperature before the test of more than 37.0°C should be referred back for medical evaluation.
Assessment of heat tolerance
- The assessment of heat tolerance is based on the body temperature which is recorded at the end of the 30-minute bench stepping exercise. Sterilized thermometers should be issued on an individual basis.
- Care should be taken to ensure that the thermometers are shaken down properly before use. AI the candidates should be seated inside the chamber for temperature recording. Thermometers must be fully emerged in a solution of disinfected at least 30 minutes before it is reused. The thermometer bulb should be placed under the armpit with the stem protruding for a period of three minutes before being read. Temperatures must be measured and recorded accurately. Any person with a reading over 37.6°C should be regarded as heat intolerant and he/she should be referred back for medical evaluation for re assessment.
- During the three-minute period men/women should sit down on the stepping bench to minimize possible post-exertional syncope (black-outs).
Temperatures.
- The HTS test should be carried out at a wet-bulb temperature of 28.0°C and dry-bulb temperature of 29.5°C. The temperatures should be measured and recorded at five-minute intervals at various locations in the climatic chamber. The permissible range of 27.7 to 28.5°C wet-bulb must be maintained. The difference between dry-bulb and wet-bulb temperatures must be controlled at 1.5°C and may not be less than 1 °C and not more than 2°C. Corrective action should be taken as soon as the temperatures deviate from these conditions.
Air speed
- The air movement in the chamber must also be controlled within the range of 0.3-0.5m/s in all areas of the chamber.
Stepping procedure
- An external work rate of approximately BOW should be maintained by a bench-stepping regimen at a fixed step rate of 24 steps per minute and a stepping height of 30 .5cm. The duration of the test is 30minutes.
- The stepping procedure should be performed in the following manner:
- The upper body should be erect, the arms should swing freely, the same foot must lead in the upward and the downward movement of any given step, both should complete the full cycle. A person is allowed to change the leading foot. The upper body may not be supported by the hands placed on the thighs and the period on the beam should be equal the period on the floor.
- Supervisors should be on the alert for signs of heat exhaustion, fatigue or imminent collapse and should not hesitate to remove a person from the test and he/she should be referred back for medical evaluation.
- Any person who stops stepping, except to regain his stride, or who leaves the chamber before the end of the test must be rejected and may not be re-subjected to HTS within 24 hours. A person who fails to complete the HTS test on two successive attempts should be regarded as unfit to perform work of a physical nature.
EMERGENCY WORK IN ABNORMAL CONDITIONS
PURPOSE OF PROCEDURE
- Barberton Mines is committed to ensure that employees are working safely and not to allow any person to work in conditions where conditions are conducive to heat related illnesses. The objective of this procedure is to ensure that employees that are required to work in conditions above 32.5 °C WB not exceeding 34.5 °C WB for the purpose of establishing better environmental working conditions, are doing it safely.
- When work has to be performed in conditions exceeding the mine standard the following procedure should be followed. The Manager Mining must be informed of the work and the purpose of the work.
- The Shift Supervisor and Mine Overseer must arrange for a site specific risk assessment before work can commence.
- Ensure that all the employees who will be involved in the work, are fully acclimatised. (completed the
- HTS and 12 Sifts Natural acclimatisation)
- The team leader (supervisor) must be briefed by the Shift Supervisor to ensure that the procedure is fully understood.
- The supervisor must be conversant with the heat treatment procedure.
Working Procedure
- The Miner must take temperatures before the work starts and during the shift. If the temperature increases above 34.5 °C WB work must stop and re-assess in order to arrange for ice-vests.
- The team must be under constant supervision and any person showing signs of heat stress must be withdrawing from the hot environment.
- The team must take regular breaks and drink cold water at least 250ml every 30 minutes. If required the team must taking turns to rest and work.
- Employees working in abnormal environmental conditions must not be allowed to work extended shifts.
- Employees must be allowed to pace themselves and to report when experience any dizziness or discomfort.
- The ambient heat load is expressed as the arithmetic mean of the dry and wet bulb temperature. The ambient conditions can be assessed determining the discomfort Emergency Heat Stress Index. (EHSI) =(Dry-bulb+ Wet bulb)/2
- Fractions of the temperatures are rounded up e.g. 24.3 use 25.
Index above 28- Implement heat stress programme.
- When the EHSI exceeds 37 hard physical and strenuous work should be stopped, or:
- when the WBGT is more than 35.
Safe work practice and supervision:
Heat stress hygiene practices are important to reduce the risk that employees may suffer from a heat-related disorder.
- Provide accurate verbal and written instructions about heat stress and heat strain.
- Encourage drinking small volumes of cool water frequently (every 20 to 30min)
- Permit self-limitations of exposure and encourage co-worker observation to detect signs and symptoms of heat exhaustion in others.
- Encourage that acceptable work rates are maintained in order to avoid heat stress by work rest cycles.
- Counsel and monitor employees who take medication that may compromise cardiovascular and blood pressure, body temperature regulation or sweat function.
- Alcohol abuse may also compromise normal body temperature regulation.
- Encourage healthy lifestyle as excessive body mass also compromise electrolyte balance during heat exposure.
- Where employees are required to work in direct sunlight it is suggested that more regular water breaks are taken where they are protected from direct sunlight.
- Employees working in direct sunlight should be supplied with wide brimmed hats for protection.
- The use of taking fluids supplements for electrolyte balance may also be a good practice to encourage fluid replacement.
- Employees should be informed that the must report any symptoms, like fatigue, nausea, dizziness and light-headedness or head ace
Monitoring
- Ensure that daily temperatures are measured especially when excessive hot conditions are experienced.
- Temperatures should be taken hourly starting from 11h00 in the morning until temperatures are below the action levels.
- Temperatures must be taken with a whirling hygrometer.
- Temperatures must be recorded as well as the EHSI
- Ensure that the persons who are recording the temperatures are trained to use the whirling hygrometer.
- Temperatures should be taken in shade.
SURFACE HEAT STRESS MANAGEMENT PROCEDURE
13.1 RISK ASSESSMENT
The ambient heat load is expressed as the arithmetic mean of the dry and wet bulb temperature. The ambient conditions can be assessed determining the discomfort Emergency Heat Stress Index. (EHSI) =(Dry-bulb+ Wet bulb)/2
Fractions of the temperatures are rounded up e.g. 24.3 use 25. Index above 28 – Implement heat stress programme.
When the EHSI exceeds 37 hard physical and strenuous work should be stopped, or: when the WBGT is more than 35.
SAFE WORK PRACTICE AND SUPERVISION
Heat stress hygiene practices are important to reduce the risk that employees may suffer from a heat-related disorder.
- Provide accurate verbal and written instructions about heat stress and heat strain.
- Encourage drinking small volumes of cool water frequently (every 20 to 30min)
- Permit self-limitations of exposure and encourage co-worker observation to detect signs and symptoms of heat exhaustion in others.
- Encourage that acceptable work rates are maintained in order to avoid heat stress by work rest cycles.
- Counsel and monitor employees who take medication that may compromise cardiovascular and blood pressure, body temperature regulation or sweat function.
- Alcohol abuse may also compromise normal body temperature regulation.
- Encourage healthy lifestyle as excessive body mass also compromise electrolyte balance during heat exposure.
- Where employees are required to work in direct sunlight it is suggested that more regular water breaks are taken where they are protected from direct sunlight.
- Employees working in direct sunlight should be supplied with wide brimmed hats for protection.
- The use of taking fluids supplements for electrolyte balance may also be a good practice to encourage fluid replacement.
- Employees should be informed that the must report any symptoms, like fatigue, nausea, dizziness and light-headedness or head ace.
MONITORING
- Ensure that daily temperatures are measured especially when excessive hot conditions are experienced
- Temperatures should be taken hourly starting from 11h00 in the morning until temperatures are below the action levels.
- Temperatures must be taken with a whirling hygrometer.
- Temperatures must be recorded as well as the EHSI
- Ensure that the persons who are recording the temperatures are trained to use the whirling hygrometer.
- Temperatures should be taken in shade.
