What is the risk of heat illness occurring?

There are several factors that need to be considered when determining if there is a risk of heat illness to workers and ways to protect them.

When identifying heat hazards and controlling heat risks, workers likely to be exposed to heat as well as with their health and safety representatives (HSRs), if any, must be consulted.

Identifying heat illness hazards

Air temperature alone cannot be used to determine whether there is a risk of heat illness. The key risk factors that need to be taken into account are:

• air temperature
• humidity (in the environment or workplaces such as laundries and mines)
• radiant heat (from the sun or other sources such as furnaces and ovens)
• air movement or wind speed
• workload (nature of the work and duration)
• physical fitness of the worker (including acclimatisation and any pre-existing conditions eg overweight, heart/circulatory diseases, skin diseases or use of certain medicines)
• clothing (including protective clothing such as overalls, coveralls and suits worn during insecticide spraying).

Is there a risk of heat illness?

If there is a risk of heat illness at work, it must be controlled. Advice may be sought from a person competent in heat assessment. They can provide recommendations about how the risk can be controlled.

Any assessment should include an appropriate heat stress index. A commonly used and recognised index is the Wet Bulb Globe Temperature (WBGT). The WBGT takes into account air temperature, radiant heat, humidity and air movement.

Adjustments are also made to take into account things such as physical workload, clothing and work organisation.
If a risk of heat illness is identified, control measures need to be put in place. Workers considered at risk due to factors such as pre-existing conditions should be assessed by a doctor.

WorkCover NSW is reminding workers to take precautions during the hot summer months and protect themselves when working in the sun to prevent fatigue.


Click here to view the Working in Heat fact sheet.

A Workcover NSW article