A union is calling for a legal limit on how hot workplaces can be – as the UK faces a heatwave that could see temperatures hit a record-breaking 41C.
A red warning for extreme heat is in place across swathes of the country including London, Manchester and York.
The GMB union said there should be a maximum temperature of 25C at workplaces, with staff allowed to wear cooler clothes and take extra breaks.
Employers should give staff flexible working and travel arrangements so that they can avoid the hottest parts of the day, the union said.
“This hot weather is great for being on a sun lounger, but if you’re trying to work through it’s no joke,” said Lynsey Mann, the GMB’s health and safety officer.
“Bosses need to do everything possible to keep workplaces cool and, more importantly, safe.”
She said simple solutions include letting people wear more casual clothing and providing water.
Ms Mann said a legal maximum temperature is in employers’ interests, adding: “Workers who are overheating aren’t going to be at their best.”
She said outdoor workers were also more likely to develop skin cancer due to high levels of UV exposure, adding that employers should provide support like extra breaks, sun cream and protective clothing like hats with neck covers.
The government already has recommendations for minimum workplace temperatures, saying they should normally be at least 16C – or 13C if the work involves rigorous effort.
The Trades Union Congress (TUC) has called for a maximum temperature of 30°C for most occupations, and 27°C for those doing strenuous work.
TUC general secretary Frances O’Grady said: “We all love it when the sun comes out, but working in sweltering conditions in a baking shop or stifling office can be unbearable and dangerous.”
What are your legal rights at work?
The Health and Safety Executive (HSE) says there is no maximum temperature because workplaces with hot processes – like bakeries, glass works or foundries – would not be able to comply with the requirement.
They have other ways of controlling the effects of hot temperatures and ensuring that people can work safely, according to the HSE.
Under the law, employers must make sure indoor workplaces stay at a “reasonable” temperature and have to manage the risk of working outdoors in the heat.
Staff are “entitled to an environment where risks to their health and safety are properly controlled”, the HSE says.
They are advised to discuss any concerns with their managers, union or workplace representatives.