How to Prevent Heat Exposure at Work

What is Heat Stress?

Heat stress occurs when the body is exposed to excessive heat, which leads to heat strain. Heat strain is the body’s physical response to this extra heat and occurs when the body is unable to cool itself down.

Heat stress is common for those working in hot conditions outdoors or in manufacturing plants with high-temperature processes.

The Body’s Response to Heat

• Widening of blood vessels
• Sweating
• Dehydration
• Increased heart rate

Heat Related Illnesses

• Heat rash
• Heat cramps
• Fainting
• Heat exhaustion
• Heat stroke

When is it Too Hot to Work?

When the body gets hot it needs to lose heat. If the heat is not lost, the body can experience a dangerous increase in core body temperature.

There is currently no New Zealand work exposure standard for heat stress. It is considered that maintaining a core body temperature below 38 ^oC is best practice. 

Heat Stress Management

Hydration – Installing hydration stations near work areas reduces the risk of dehydration.

Rest Breaks – Taking regular breaks in a cool or shaded area helps workers maintain a good core body temperature.

Appropriate Clothing – Wearing breathable fabric clothes helps improve the evaporation rate of sweat, and therefore increases the cooling effects of sweating.

Sun Protection – Ensuring workers are protected from the sun with hats and sunblock is key to managing heat exposure.

Temperature and Humidity Monitoring – Paying attention to weather conditions such as high humidity and temperature is essential, especially in summer.  At higher humidity, heat stress responses may be experienced at lower temperatures as the body’s ability to cool down by sweating is hindered by the moisture saturation of the air.

Training – Training workers to recognise the signs of heat stress allows workers to remove themselves from the situation and cool themselves down before heat stress is escalated.

Increase Air Circulation – Increasing air flow over workers increases the evaporation rate of sweat and helps keep core body temperature stabilised.

Insulate and Isolate Radiant Heat Sources – Insulating radiant heat sources will reduce the heat exposure of workers from those sources. This includes installing barriers around hot equipment or having a separate operators booth to keep workers away from areas and machinery.

Adjust Workloads – Adjusting the intensity and duration of physical activities based on current heat conditions helps reduce the chance of heat stress on a worker.

Work Scheduling – Avoid working during the hottest parts of the day. Plan work for the cooler hours of the day, such as early morning or late afternoon.

Why is Heat Stress Management Important?

Managing heat stress at work is essential for worker wellbeing and productivity. Applying these heat stress solutions effectively reduces the risk of heat-related illnesses.

For further information regarding heat stress or heat stress monitoring in your workplace, visit our page on heat stress monitoring.