Red extreme heat warning; How hot is too hot to work?
With the UK facing extreme heat warnings this week and temperatures set to soar, business leaders and employees alike are asking the same question: How hot is too hot to work?
As HR professionals and business owners, how we respond to these spikes in temperature doesn't just impact productivity, our response ultimately defines our workplace culture and how employees perceive the company ethos. Of course, we cannot control the weather, but we can control our response to it. And this can make all the difference.
Here is what you need to know about the legalities, your responsibilities, and how to keep your team safe and motivated during extreme heat.
The legal bit: Is there a maximum temperature?
First, it is important to clear up a common misconception: there is no law in the UK specifying a maximum working temperature.
The reason a definitive upper limit doesn't exist is because every workplace is unique. In many indoor environments, for instance, bakeries or kitchens, high temperatures are a year-round reality of the job, not just a seasonal issue. This makes the question of how hot is too hot, a rather grey area.
That said, employers are legally bound by general health and safety laws. Under these regulations, employers are required to:
Maintain a workplace temperature that is "reasonable" and comfortable.
Provide clean, fresh air through proper ventilation.
When the Met Office issues amber or red extreme heat warnings like this week, employers must use their judgment and conduct their own risk assessment. Whether it becomes necessary to alter working arrangements or send people home depends on a mix of environmental and personal factors: humidity, air movement, physical exertion, and the specific health needs of your workforce.
What to do if employees complain it’s too hot
If employees are flagging that the heat is becoming unbearable, they are giving you an early warning sign that safety or morale is at risk. Here is how HR can proactively manage the situation and keep operations running smoothly.
1. Adjust the environment and routines
Embrace flexibility: Consider shifting working hours so staff can start earlier or finish later, avoiding the midday heat.
Eliminate unnecessary travel: Commuting in extreme heat can be draining. If roles allow, consider working from home to keep people out of packed trains and traffic jams.
Relax the dress code: This costs the business absolutely nothing but instantly boosts comfort, morale, and goodwill within the team.
2. Protect vulnerable workers
Remember a one size fits all policy won’t be right for everyone. HR should prompt managers to look out for specific individuals who face higher risks in extreme heat, including:
Pregnant employees.
Staff with underlying medical conditions (such as cardiovascular or respiratory issues).
Employees taking specific medications.
3. Boost morale (and hydration)
Keep cool: If permanent air conditioning isn't an option, hire temporary AC units or ensure there are desk fans available for everyone.
Prioritise hydration: Hand out chilled bottled water, stock the communal fridge freezer with fresh fruit and ice lollies or surprise the team by hiring an ice cream van for an afternoon. Small gestures go a long way.
4. Support carers
· Extreme heat frequently forces schools and nurseries to close at short notice. Be prepared to support working parents and those with caring responsibilities by offering temporary flexibility or adjusted deadlines.
5. Check union agreements
· If your workplace recognises a Trade Union (TU), check your collective agreements. Some workplace frameworks have pre-agreed trigger temperatures that dictate exactly when specific actions or breaks must be introduced.
Hot weather or not, at the end of the day, business must go on, and most people understand that work needs to continue.