With temperatures set to reach 30C again today after barely any respite overnight, offices are again sweltering.

As the mercury rises, many are wondering how hot a workplace can be before you can use it as an excuse to head outside.

Here's what the Government says:

"During working hours the temperature in all indoor workplaces must be reasonable.

There’s no law for minimum or maximum working temperatures, eg when it’s too cold or too hot to work.

However, guidance suggests a minimum of 16ºC or 13ºC if employees are doing physical work.

There’s no guidance for a maximum temperature limit.

Employers must stick to health and safety at work law, including: keeping the temperature at a comfortable level and providing clean and fresh air.

Employees should talk to their employer if the workplace temperature isn’t comfortable."

So not much chance of escaping the office and enjoying a siesta in the sun.