Can I go home from work if it's too hot?

The law does not set any maximum temperature in the workplace, but says temperatures in indoor workplaces must be “reasonable”.

But an employer which believes happy staff are productive might want to go further than the law requires.

Claire Merrit, partner at law firm Paris Smith, said: “Employers have an obligation to keep employees safe in the workplace, however health and safety rules set no maximum temperature for the workplace. It is therefore for an employer to take steps to understand what is reasonable and reduce risk to staff.

“Unfortunately the problem is that different people react differently to heat. We are all used to the frequent workplace disputes around the temperature. There is always someone who is too hot and someone too cold.”

She added: “Steps that can be taken to minimise the impact of heat can be to relax dress codes, providing fans and, of course, ensuring air conditioning is well maintained. You could change rest breaks and provide shade if working outside. Some employers also take the opportunity to reward staff with ice creams or cold drinks, which can raise morale and keep employees motivated.

“I am afraid staff cannot go home due to heat unless authorised by their employer to do so, but they certainly should raise any concerns with their managers. Managers should look into any concerns carefully. If staff are feeling ill, then this needs to be treated as any other sickness absence.”

Tom Doherty, managing director of the HR Dept, which provides outsourced HR support, said: “Legally, there is no maximum working temperature – however, I think everyone should recognise that common sense should prevail when dealing with working in hot weather from all parties.

“All of this advice comes with the caveat that it needs to fit with the business and its operations too. Whether an employee is working inside or outside, relaxing the dress code, where appropriate, can help.

“Be flexible about working hours – start earlier and finish earlier. Consider not having people out in the sun during the hottest part of the day. Increase the opportunity for people working to have additional one-off breaks for refreshments. Ice lollies and cooling drinks always go down well.

“Have workers who operate outside, got adequate protection, such as hats, sunglasses, sun cream etc? Every working environment is going to be different, so finding some practical adjustment could help people cope a bit better."

Sally-Ann Hall Jones, chief executive of Reality HR, said: “While it’s an urban myth that there is a legal ‘maximum temperature’ that a workplace should be, employers are obliged to make sure working conditions are reasonable.

“In many cases – particularly for employees who work outside, or in offices that suffer from a lack of air conditioning or poor ventilation – there are simple common sense steps that can be taken to ensure staff stay comfortable and safe.”

She said these could include relaxing the dress code, making sure air conditioning and fans are in good working order, ensuring adequate protection for people working outdoors, and making sure the water cooler is well stocked.

Companies should consider vulnerable people such as older workers, pregnant women or those with disabilities, and should make sure first aiders were aware of those who might be vulnerable.

The Health and Safety Executive (HSE) says “during working hours the temperature in all workplaces inside should be reasonable”.

The HSE also advises that – if staff do complain about the temperature – the employer carries out a ‘thermal comfort risk assessment, according to Hugh Reid, solicitor specialising in employment law.

He said employers should switch on the air conditioning or supply desktop fans, make sure there is plenty of drinking water, relax dress codes and make sure outdoor workers were provided with appropriate clothing, sunscreen and sunglasses. They should make sure staff take frequent breaks.

He said staff were not entitled to go home “ unless they feel unwell and need to take sick leave”.