Heat stress may affect people in all parts of Western Australia during our summer months and may affect workers at some workplaces throughout the year. The effects of heat stress range from discomfort to life threatening illnesses such as heat stroke.
Read more on how to avoid heat illness when working in hot conditions.
Hot workplaces are common in Western Australia. Heat may result from:
- hot climatic conditions
- heavy work in moderately hot conditions
- hot work processes (such as welding or working in foundries)
- radiant heat from the environment and surroundings
- work where heavy protective clothing must be worn or
- any combination of these factors.
The Work Health and Safety Act 2020 requires the employer or person conducting a business or undertaking (PCBU) to provide and maintain a working environment in which workers are not exposed to hazards or risks to their health and safety. This applies to any risk to safety and health, including illness from working in heat conditions.
What is heat stress?
Heat stress is the total heat burden to which the body is subjected by both external and internal factors. Heat stress causes increased blood flow to the skin, which allows the release of heat. When physical work is performed, blood is diverted to the muscles resulting in a lower release of heat through the skin.
The body must therefore balance the heat transferred into the body, the heat generated in the body and the heat coming out of the body.
Heat illness
If the body can’t balance its heat inputs, heat stress may lead to heat illness (or heat strain), a physical response designed to reduce body temperature.
Types of heat illness include:
- discomfort - flushed skin, increased sweating, heat rashes (prickly heat)
- mild heat illness - feeling tired, weak or dizzy, cramps, reduced work capacity, reduced attention span, irritability
- heat exhaustion - fainting, headache, low blood pressure, nausea, clammy, pale or flushed skin, normal to high body temperature of up to 39°C
- heat stroke - irritability, confusion, speech problems, hot dry skin, convulsions, unconsciousness, body temperature above 40°C, cardiac arrest - potentially fatal, a life threatening condition that requires immediate first aid and medical attention.
Are some people more prone to heat illness than others?
Some people are less tolerant of heat than others and working in hot conditions may aggravate their pre-existing illnesses and conditions. People who are at greater risk of heat illness and should heed medical advice are those who:
- are medically unfit
- are on certain medications
- overweight
- have heart disease
- are pregnant
- abuse alcohol
- are not acclimatised to the hot conditions.
Acclimatisation can take 7-14 days to take effect and can be reduced after 3 days away from hot work. Acclimatisation is entirely lost after 4 weeks away from hot work and so medical advice should always be followed.
Managing the risk of heat illness
In identifying, assessing and controlling risks associated with heat illness, employers should consult with workers likely to be exposed to heat as well as with any elected health and safety representatives.
Reducing the risk of heat stress
There is a recommended order of control measures that eliminate or reduce the risks of injury or harm and often a combination of controls will be necessary.
How should heat illness be treated?
When one of your workers is experiencing heat illness:
- ensure the person rests in the coolest available area and drinks cool, but not cold fluids
- provide an electrolyte supplement or sports drink if available.
If the symptoms do not reduce quickly or if symptoms of heat stroke are present, contact a doctor, nurse, ambulance service or first aid officer for assistance.
Heat exhaustion
Symptoms of heat exhaustion can include:
- fainting
- headache
- low blood pressure
- nausea
- clammy
- pale or flushed skin
- normal to high body temperature (up to 39°C).
To treat heat exhaustion:
- move your worker to a cooler environment with good air movement
- loosen their clothing and if necessary remove unnecessary clothing
- provide cool, but not cold fluid, for them to drink if they are conscious
- sponge them with cold or iced water
- seek medical attention if the person does not recover quickly or vomits.
Heat stroke
Symptoms of heat stroke can include:
- irritability
- confusion
- speech problems
- hot dry skin
- convulsions
- unconsciousness
- body temperature above 40°C
- cardiac arrest - potentially fatal
- a life threatening condition that requires immediate first aid and medical attention.
To treat heat stroke:
- follow the DRSABCD action plan
- immerse the person in a bath of cold/iced water. If immersion is not practical, dip towels in iced water and place them on the person
- apply cold packs/wrapped icepacks to the neck, groin and armpit areas
- call 000 for an ambulance
- provide water to drink if the person is fully conscious and able to swallow
- seek urgent medical attention if the person becomes unconscious or has a seizure.
Make the job safe - talk about health and safety at work
If you believe there are problems with heat stress at your workplace you should discuss them with your employer and your health and safety representative.
Other sources of information
- Heat stress basic calculator – WorkCover Queensland
- Skin cancer and outdoor work WorkSafe/Department of Health (WA)/Cancer Council WA
- Guide on exposure to solar ultraviolet radiation Safe Work Australia
- ACGIH TLVs and BEIs 2020 (available for purchase from ACGIH)
- Heat Stress Checklist - Risk Assessment Work Sheet Health and Safety Executive (UK)
- Protecting Workers in Hot Environments 1995 Occupational Safety and Health Administration (OSHA, USA)
- Protecting workers from heat illness National Institute for Occupational Safety and Health (NIOSH, USA)
- A Guide to Managing Heat Stress: Developed for Use in the Australian Environment – AIOH (available for purchase)
- Working safely in hot conditions