I’m writing this from the North East of England and typically the weather here today is what my teenagers would describe as “meh”. But for the past couple of weeks the country has been basking in somewhat of a heatwave, and as a typical Brit I’ve become a bit obsessed with the weather and the heat, the lack of rain, the lack of wind and of course, the glorious sunshine. At the weekend I am standing in Kielder forest helping at a sports event and I think I will take everything, from wellies to sunscreen, warm hoodies and shorts as the forecast is for sun wind rain and probably a plague of midges!
But in all seriousness, the thermal environment (as it is more formally known) is not just a British hobby but an essential consideration for many workplaces. Whilst I am now primarily a tutor/trainer/freelance writer and office or classroom based, in the past I have looked after the health and safety of factory and chemical plant workers who can be exposed to more extreme thermal environments. I first pondered this in July 2022 and this is an extension to my last blog after the publication of new guidance.
Thermal comfort vs heat stress
So what are we actually worried about? Well, as anyone who has been in charge of the central heating controls will know, we all have a different perception of what is a “comfortable” workplace temperature. The HSE on their temperature micro site Temperature: Thermal comfort (hse.gov.uk) talk of thermal comfort as not being “uncomfortably hot or cold”. ISO 7730 refers to ‘That condition of mind which expresses satisfaction with the thermal environment.’ The consensus is that thermal comfort relates to being “satisfied” with the workplace temperature. Finding a temperature in a classroom where everyone is happy is the Holy Grail of trainers, and I’m not belittling this in the slightest, but nobody is at real risk of harm here (except perhaps the tutor). The same is not true however for extreme thermal environments. Now we are talking not about discomfort, but in fact a significant risk to safety due to exposure to heat (or cold – but in this blog I’m focusing mainly on heat stress).
Risk of heat stress
There are some workplaces where high temperatures are unavoidable, such as kitchens, foundries, glass manufacturing and many factories. This risk exists throughout the year and is in this respect should be controlled well as it is “the norm”. Other environments are more readily influenced by the weather and it is these areas that are perhaps more difficult to manage. After all, for many of us hot weather is a transient feature of summer months, surely it’s not worth worrying about a “bit of sun” occasionally. Wrong. Extreme environments can result in heat syncope (fainting), heat exhaustion and (most worryingly) heat stroke.
Examples of heat syncope have been reported at the rehearsals for this year’s Trooping the Colour, when guardsmen allegedly fainted in the June sunshine in their heavy ceremonial uniforms, and we have seen fire fighters battling grass fires in incredible temperatures. Heat exhaustion is a lesser (but still concerning) condition resulting in symptoms such as headaches, nausea, dizziness, cramps, pale cool and moist skin and excessive sweating. Heat stroke is a much more serious condition, with symptoms such as hot, dry skin, fast breathing or shortness of breath, very high temperature, seizures and loss of consciousness. And heat stroke can be fatal and requires immediate emergency medical attention.
From even this brief blog I hope you can see that if you are in an environment where heat stress is a potential, first aiders must know what treatment is required. An excellent summary can be found in new EU-OSHA guidance at Heat at work – Guidance for workplaces | Safety and health at work EU-OSHA (europa.eu). But then again if you are in the UK the HSE First aid guidance document L74 suggests that training should be tailored to the workplace hazards anyway.
Assessing the risk of heat stress – HSE tools
So how do you know if you have a problem? And how hot is too hot? The UK’s Workplace (health, safety and welfare) regulations doesn’t establish a maximum workplace temperature, merely that it should be “reasonable”, but that is of course subjective. Well of course the HSE has produced an excellent micro site on the thermal environment and here you can find a very helpful “Heat Stress Checklist” which can help you to assess and manage the risks. It considers the impact of the main parameters that contribute to heat stress – air temperature, radiant temperature, air velocity, humidity, clothing and work rate. For each there are subjective descriptions used to assess the potential to contribute to heat stress, and these are combined in an assessment grid on the last page which indicates whether there is a risk of heat stress, or whether physiological monitoring is required.
Heat Stress Indices
NEBOSH diploma graduates may remember something in the dim and distant past about heat stress indices, and the methods of measuring the thermal environment using wet bulbs, dry bulbs, whirling hygrometers and other such devices that we imagine are only to be considered around exam time. However more and more organisations are using standardised heat stress indices such as ISO 7730 together with the fabled “wet bulb globe thermometer” (it really does exist outside of NEBOSH land!) in order to measure the parameters mentioned above. This can be used to assess conditions indoors and outdoors and also considers how well acclimatised workers are, the airflow and their work rate.
If you can’t stand the heat, get out of the kitchen – literally!
Controls can then be implemented to reduce the risk. Breaks in a cool environment with cooling drinks will help, as will reduced work rate, changed work hours to avoid the hottest parts of the day, portable cooling devices, chilled jackets, lighter weight work wear. There are a myriad of options that can be considered and recorded in the assessment, and whilst it unlikely to be a “perfect” solution in my experience the goodwill generated by assessing, listening and trying will be as valuable as the improvements.
The impact of weather conditions
I started by being almost flippant about the weather – but please don’t forget that this could contribute significantly to heat stress in the workplace. Your workplace could be a factory or a foundry in which case you may well be acclimatised, but it could equally be a beach, farm, forest or a palace courtyard, and the weather may be more or less important accordingly, and people shouldn’t be fainting with the heat at work whatever their role. Tragically we have in the past failed to assess the impact of weather conditions and deaths have occurred – in 2013 three SAS reservists died when they were on a 16 mile selection march carrying heavy (27Kg) packs one of the hottest days of the year. Brecon Beacons SAS deaths: Failings were ‘serious and widespread’ – BBC News. The heat stress indices can be used to assess conditions on the day to determine what controls are necessary, and after all saying “not today” is often an option.
Outside of the workplace
What about sporting events and training activities? Can we use the lessons from the workplace to assist with decision making? As a keen triathlete and runner (load of enthusiasm, zero talent) I see the lengths that event organisers go to in order to manage issues posed by high (and low) temperatures. I’ve seen cold swims shortened, additional water stations added on hot days. I’ve had the joy of a wet sponge on the neck on a toasty marathon and seen warm tents ready for anyone who needed assistance out in the wilds of Northumberland.
Good event organisers think about the thermal environment and keep the participants safe. Goodness at the world cup they air conditioned football pitches! However when the Sheffield Half Marathon was cancelled in 2014 as there was no water delivered for the aid stations for the 4000 runners on a warm day people criticised the decision. This included the former local MP and sports minister who, of course, blamed health and safety Former minister criticises ‘risk averse’ sport culture – BBC News. Taking risk based decisions to ensure the safety of people is not the same as being “risk averse”, it’s being risk aware. There will always be people who say “it’s all health and safety gone mad” and that annoys me for a moment but then I remember, it’s not them we do this for, it’s for the people they are putting at risk.
RRC Lead Tutor