Heat stress (also known as heat exhaustion) occurs when the body isn’t able to control its internal temperature properly. This can be caused by environmental factors such as the air temperature or humidity, task-based factors such as working especially hard or quickly, and the clothing that is worn while working, including Personal Protective Equipment (PPE).
PPE serves to provide a last line of defence between the worker and a hazard where no other suitable means of protection is possible – for example, a hazardous materials suit protecting a healthcare worker from an infectious disease.
While direct ventilation and filtration is more effective, it may not always be reasonable. For example, if you were responding to an unknown virus, or providing assistance to someone in their home.
It’s always better to try and find another way to control a risk before turning to PPE, but where PPE is required, it needs to be appropriate.
One of the main issues with PPE is heat and heat stress.
While not always a significant risk to health, being uncomfortable can become stressful or irritating.
An uncomfortable temperature can not only mean that you’re sweating and becoming dehydrated, it can often impact the willingness of workers to wear vital equipment, for example taking off a hard hat because it’s too hot, or not wearing appropriate clothing for the risk.
Not only can being too hot be uncomfortable, it also can lead to heat stress or heat stroke, having a significantly negative effect on our bodies and cognitive processing.
Effects of heat stress on the body
Heat will cause us to sweat and dehydrate. This leads to:
- Poorer concentration
- Poorer judgement
- Confusion
- Headaches
- Fatigue
- Muscle soreness
- Dizziness
- Nausea
- Faster heartbeat
- Faster breathing
- Weakness
If significant heat stress is experienced leading to heat stroke it can also lead to:
- Giddiness and delirium
- Fainting
- Convulsions
- Loss of concentration
- Death
Heat stress and heat stroke can make working harder, or even more dangerous, especially where a job requires constant concentration.
Sweat and eyewear
Sweat while wearing PPE can also cause visors, goggles, and cloaked hoods to steam up if the PPE isn’t suitable for the conditions. This can affect people differently based on a number of factors, including how much they sweat and the shape and fit of the PPE.
Poorer visibility can significantly impact a worker’s ability to carry out their work, and more importantly, their ability to work safely.
Barriers to breathing
Respiratory Protective Equipment (RPE) and any other type of PPE that covers the face can have a restrictive effect on breathing. Heat can make it harder to breath, especially if the worker has any existing respiratory difficulties, such as asthma.
What can be done?
Welfare legislation does not provide a set minimum or maximum temperature in the workplace, the workplace just needs to be classified by a manager as ‘comfortable’. Unfortunately, this means that there is room for not only individual differences, but also for the manager to say that the temperature is comfortable, then return to their nicely airconditioned office or shaded cabin.
Management have a responsibility to ensure a safe workplace. This includes ensuring that the use of PPE doesn’t result in injury or ill-health.