The Science of Heat Stress: What Every Lone Worker Should Know

We’re all familiar with the symptoms that we might feel when we get too warm on a blazing summer day. But for some workers, a hot environment doesn’t just happen in summer. Employees in many different careers, ranging from healthcare to manufacturing to food preparation, may have to work in high temperatures year-round.

That’s challenging enough – but what complicates the situation is when a person is working alone. That’s when lone workers and employees need to take extra care and put in place protections against the harms of heat stress.

In this article, we’ll talk about what heat stress is, what factors play a part in it, and what can be done to keep lone workers as safe as possible in the heat.

What is heat stress?

‘Heat stress’ is a term that describes a range of physical symptoms that result when a person gets too hot for their body to handle. Ordinarily, mechanisms like sweat are enough to help a person cool down to a healthy temperature. But when these mechanisms aren’t enough, that’s when heat stress starts to set in.

On the milder end of the scale are symptoms like heat rash and difficulty concentrating. Workers who are too hot may experience fainting or a strong thirst, too. Interestingly, muscle cramps can also be a sign of heat stress – they occur when a person has sweated too much.

When heat stress becomes more severe, it can include heat exhaustion, with symptoms like clammy skin, nausea, headache and a very fast heartbeat. And the most serious level of heat stress is, of course, heatstroke.

An important note: The NHS encourages you to call 111 if you are concerned about symptoms of heat exhaustion. If someone has signs of heatstroke, you should call 999. The NHS lists the relevant symptoms of heatstroke as:

• Body temperature that’s very high

• A rapid heartbeat, breathing fast, or feeling short of breath

• Confusion

• Seizures

• Lack of coordination

• Skin that is hot but isn’t sweating and may appear reddened (though this may not be easily visible on all skin tones)

• Passing out/losing consciousness

Another sign of heatstroke is when a person is “still unwell after 30 minutes of resting in a cool place, being cooled and drinking fluids.”

What factors raise the risk of heat stress?

It is certainly true that a lone worker might face heat stress on a hot day. But that’s not the end of the story. According to the UK government’s Health and Safety Executive (HSE), there are numerous elements that affect a worker’s likelihood of developing heat stress.

An HSE checklist for assessing risks of heat stress identifies six factors to consider.

Three of them can be related to weather – the checklist asks about humidity, the air temperature and how much heat is being given off by objects, including the sun. It’s important to separate these factors, because they can have quite different effects.

For example, a person could be working outdoors on a freezing cold, damp day with a heavy machine that’s giving off a lot of heat – that would be a cold air temperature and high humidity but high radiant heat. On the other hand, a day with hot air temperatures and hot sunlight (radiant heat) but low humidity might not feel as unpleasant as a similar day with high humidity.

Another factor to think about is whether any air is blowing, and if so, how quickly it’s blowing and how cold or warm it is. This could mean the wind, fans, or a manufacturing machine that blows out air.

The details of a person’s work play a part too. The checklist asks about how strenuous the work is and how heavy the clothing a person has to wear is. For example, a doctor helping someone who has an infectious disease might be wearing very heavy protective clothing but moving slowly. On the other hand, a gardener might be wearing a t-shirt and shorts but working hard digging and moving heavy objects.

On top of all these considerations, a worker’s medical information can also be important. People can have medical conditions that mean they overheat more easily. And older people’s bodies are sometimes less able to cool down effectively, too.

And lastly, training and experience matter. A labourer who has been working with a kiln for ten years may be more familiar with heat stress management and more able to identify early signs of heat stress. On the other hand, a new hire who hasn’t yet learned about the dangers of heat stress could be much more at risk – they might not even know what symptoms to be aware of.

Managers of lone workers should be considering as many of these factors as possible in relation to their lone workers. While an employer shouldn’t pry into personal medical details, some jobs involving high-heat environments may require a physical examination by a doctor to ensure the worker is cleared to take on their duties.

And lone workers should know all of these factors, too, so that they can take action to lower their risk if necessary.

Steps that can reduce heat stress risks

When a lone worker or their manager is thinking about how to reduce the chance of heat stress, they can start by looking at the factors we’ve listed, such as:

• Air temperature and humidity

• Wind or air movement

• Heat from objects/machinery or the sun

• Clothing

• Working patterns such as time spent in heavy work

• Training and knowledge about how to combat heat stress

Let’s look at how managers or a lone worker might combat each factor:

• Air temperature – Provide air conditioning

• Wind or air movement – Provide fans

• Heat from objects or the sun – Have workers leave the area or move away when a machine is hot, or install window shades to keep out the sun

• Clothing – Reduce layers and density of clothing when it’s safe to do so

• Working patterns – Provide breaks during heavy labour, or time the heavy labour to take place during a cooler part of the day

It’s often also important to ensure workers have enough cool water to drink to replenish fluid lost to sweat.

Measures like these aren’t enough, though. Sometimes, it’s unavoidable that a worker will have to experience excessive heat, even after every effort has been made to make the environment more comfortable. And all the steps we’ve listed above are just ways to reduce the risk of heat stroke – they can’t eliminate the danger entirely. For one thing, it’s always possible that a worker might have an unknown medical condition that makes them react particularly badly to heat.

So, when a lone worker is going to be facing excessive heat at work, there needs to be a plan in place for getting that person help fast if they do end up experiencing heat stress.

Getting help with heat stress when you’re alone

One crucial point to remember is that heat stress can cause symptoms like confusion, fainting, and lack of coordination. In other words, the symptoms of heat stress can make it difficult for a lone worker to call for help with heat stress.

That’s why lone workers need an easy and fast way to send an SOS call even when they’re starting to feel unwell from heat stress. Otherwise, they could become seriously ill with no-one around to even notice that something is wrong.

The answer to this problem is a lone worker alarm – a simple device with a single SOS button that can be pressed to call for help. When confusion from heat stress strikes, a lone worker alarm means that the alarm wearer doesn’t have to struggle to get their cell phone and think through dialling it. All they have to do is press their SOS button – and the lone worker alarm is body-worn, so the button is always within reach.

What if a lone worker ends up fainting before they can even press their button? That’s where a backup feature called automatic fall detection kicks in. With this function, sensors in the device are constantly assessing whether its wearer has fallen or not. If the device’s algorithm decides that it’s sensed a fall, the alarm will send a call for help automatically.

Get trusted protection for lone workers with SureSafe

The UK government’s Health and Safety Executive states that employers of lone workers must monitor lone workers. Employers must also “keep in touch with them and respond to any incidents.”

A lone worker alarm is a simple yet highly effective step toward managing the risks of lone work and of heat stress in the workplace. And ours at SureSafe has GPS tracking as well as an SOS button and automatic fall detection. That way, if a worker does make a call for help, managers and emergency teams know where to find them – fast.

Curious to learn more about how lone worker alarms could help you or your workers? Just reach out to us to learn more about your options and how it works! You can call us on 0808 189 1670, talk with us through our live chat or just request a call back.