When is it too hot to work during a heatwave?

The Met Office has issued a red warning for extreme weather in some parts of England as forecasters predict temperatures to soar way above 30C.

In fact, meteorologists predict that there is a one in three chance that the UK's top heat record of 38.7C may be broken next week. The warning indicates that the extreme heat will carry the potential to cause severe illness to the population and may even threaten life in some cases.

With this in mind, many workers may be wondering if it's too hot to work safely during this period. The TUC workes' Union is urging bosses to allow for flexible working and to relax dress codes to keep staff safe and comfortable.

Read more: Met Office issues first EVER red weather warning for 'extreme heat'

It has also recommended that workers be allowed to take frequent breaks to help stay cool. According to the UK government agency, Health and Safety Executive (HSE), there's no law for maximum working temperature, or when it's too hot to work.

However, guidance suggests a minimum of 16C or 13C if employees are doing physical work. Employers must stick to health and safety at work law though, which includes keeping the temperature at a comfortable level, sometimes known as thermal comfort, and providing clean and fresh air.

The TUC has revealed that it wants to make it illegal for workers to work indoors in temperatures above 30C and to enshrine protection for people working outside or driving also. “An employer must provide a working environment which is, as far as is reasonably practical, safe and without risks to health," the TUC explains.

"In addition, employers have to assess risks and introduce any necessary prevention or control measures." The HSE explains: "A meaningful maximum figure