Heat stress risk assessment

When undertaking a heat stress risk assessment it is recommended that you take a staged approach. A diagram of what happens at each stage of a heat stress risk assessment is provided on these web pages. This diagram is a means of helping to understand the activities that need to be undertaken at each stage.

Step 1: Identify hazards

1. Look - Visually inspect the workplace to identify heat stress hazards (e.g. looking for a heat source, are workers wearing PPE etc?)
2. Read through accident and productivity reports. Can any accidents be attributed to heat stress (e.g. fainting, confusion, poor concentration etc)? Do accidents increase during periods of hotter weather?
3. Listen to your workers. They are experts in their jobs.

Step 2: Decide who might be harmed and how

1. Inexperienced workers, young workers, trainees, contractors, cleaners, maintenance workers and visitors may require training.
2. Experienced workers with infrequent exposures may also require training. They may be used to the job, but not to working in the heat.
3. Health status of workers is important. Identify those who might be added risk to heat stress? Consult a physician if you are unsure.
4. What happens if things go wrong? Put emergency procedures in place. Rehearse emergency procedures. Consult a physician if you are unsure.
5.Plan for the unexpected. Consider the nature of the task, where it is being performed, what the hazards are and what sorts of things may go wrong. Establish a chain of command.

Step 3: Evaluate risks and decide whether existing precautions are adequate or should more be done

1.Think before you start - Is it necessary to work in the heat? Can the job be redesigned? Can the environment/PPE/work rate be changed?
2. Planning and training are crucial
3.Conduct a risk assessment and interpret the results. Use the following methods in your heat stress risk assessment:

3.1 Basic Risk Assessment to Identify Hazards
3.2 Qualitative Risk Assessment using the Observation Checklist
3.3 Quantitative Risk Assessment using the WBGT index

4. Draw up an action list. Can you get rid of the hazard altogether? If not, how can you reduce the risk of heat stress? A possible order for problem solving may include:

4.1 Try a less risky option – e.g. wait for the temperature to reduce;
4.2 Prevent access to the hazard – e.g. only acclimatised workers;
4.3 Organise work to reduce exposure – e.g. work-rest schedules, job rotation, team rotation, more workers on job;
4.4 Issue personal protective equipment – e.g. aluminised garments for those exposed to high radiant temperatures;
4.5 Provide welfare facilities – e.g. first aid and emergency procedures.

Step 4: Record your findings

1. Implement a formal reporting procedure that is incorporated into current risk assessment reporting procedures for other hazards. Record measures taken, indices used, and outcomes. Describe interpretation of assessment. Report any communication between medical experts, thermal experts etc. Record findings of discussions with staff, review of accident statistics, productivity variations etc.


Step 5: Review your assessment and revise if necessary

1. Review control options and implement controls where appropriate. Do your employees think there is still a problem? Has there been a reduction in unsafe actions, accidents, illnesses, absenteeism etc? Has there been an increase in productivity, worker satisfaction, etc?
2. Frequent Exposures: Be aware that new equipment, new manufacturing methods, new PPE, etc, may all contribute to a change in the risk of heat stress. If any changes significantly alter the risk of heat stress, conduct a heat stress risk assessment;
3. Infrequent Exposures: Conduct a risk assessment prior to each exposure. Ensuring your controls are in place, that training has been given, emergency procedures are in places, etc.