Frequently Asked Questions About Heat Stress in the Workplace

The following are some common sources of thermal stress.

• High humidity
• Dehydration
• Physical activity that increases internal body heat
• Lack of ventilation
• Direct sunlight such as when working on roads or agriculture
• Working close to a heat source such as a furnace
• Taking insufficient breaks
• Not acclimatised to working in the heat
• Wearing a large amount of personal protective equipment

It is important not to underestimate the impact of these factors when dealing with heat stress. Ventilation helps with reducing humidity and when working close to a heat source and using fans can help with air movement. Working under direct sunlight can often be avoided by scheduling work in the early morning and taking proper breaks will give the body a chance to regulate its temperature after intense physical labour.

Water is recommended as the best hydration solution against dehydration, however rehydration solutions can also assist in replenishing lost fluids and electrolytes. Solutions like the Aqualyte Rehydration Solution have been scientifically formulated to maximise the body’s fluid absorption rates to help manage heat stress over prolonged periods. On the other hand, drinks classed as diuretics such as tea and coffee or other highly caffeinated drinks should be avoided as they can dehydrate your body.

There are various heat-related symptoms that can arise from the body overheating. The following is a non-exhaustive list of the effects of excessive heat.

• Heat rash
• Heat cramps
• Fainting
• Dehydration
• Heat stroke
• Burns
• Reduced concentration

Identifying heat stress exclusively from the symptoms can be subjective and problematic when work is already underway. Heat stress monitors are used to measure heat levels both prior to and during work to help objectively identify when safe levels are exceeded. Heat stress monitors such as the TWL-1S Heat Stress Monitor or QUESTemp QT-32 Portable Heat Stress Monitor are commonly used as part of workplace heat stress management programs to monitor heat stress parameters including heat stress indices Thermal Work Limit (TWL) and Wet-Bulb Globe Temperature (WBGT).

As there are various contributing factors that make working in excessively hot conditions hazardous, there is no workplace exposure standard or limit, with temperature alone not being enough to measure danger. Humidity, how physically taxing the work is, air flow and a variety of other factors also influence the level of risk. Work conditions are instead required to be of minimal risk to workers to a reasonably practicable extent. This means that although there is no maximum temperature where work must stop, businesses are required to ensure that working conditions do not endanger the health and safety of employees.

As there is no specific heat exposure limit, heat stress assessments should be conducted in regard to the workplace conditions, demands of the particular job and the individual worker’s attributes. This can help employers identify the risks in a specific work environment to inform a plan of action. A heat stress calculator can be used in a basic assessment to give an initial review of threats that may cause heat stress in the workplace.

If a worker finds the heat to encroach on their safety, a Health and Safety Representative has the authority to allow workers to cease working. This can only occur if there is a reasonable concern that a major health or safety risk exists, and the business has been consulted in attempt to resolve the issue if the risk is not extremely imminent. Safe Work Australia provides a useful checklist that can be used to help manage the risks of working in heat.

Fair Work Australia does not have a policy on working in the heat, however workplace health and safety regulations do require employers to ensure that workers are sufficiently protected from heat stress and that their working conditions will not cause any harm to their health. The Model Code of Practice: Managing the work environment and facilities from Safe Work Australia enforces monitoring on prolonged exposure to extreme heat and requires risks to worker health to be minimised as much as is reasonably practicable.