The UK's first red extreme heat warning came into effect on Monday, with forecasters warning temperatures could reach a sweltering 40C.
With temperatures rising to record levels on Tuesday in the UK, many are concerned not only about getting to and from their place of employment but also the conditions they will have to work in.
Although millions now have the benefit of working from home or in an air-conditioned office, vocations such as being a nurse, chef or construction worker, means having to endure sweltering temperatures in full uniform during their shifts.
There are rules around minimum working temperatures in the UK, but there are no laws for maximum temperatures.
There have been calls by several trade unions to impose a maximum working temperature for workers in the UK.
But this doesn't mean you have no rights, so what protections are there?
What if it is too hot to work?
You have no legal right to say it is too hot to work, although that does not mean you can't tell your boss this and they may listen.
The Health & Safety Executive (HSE) says the minimum temperature for working is 16C or 13C if the work involves physical exertion.
Your employer does have to consider "duty of care" which is their legal duty to ensure you are safe in the workplace, but there is no hard-set rule regarding temperature.
The HSE says employers have a responsibility to ensure that working conditions are "reasonable" but there's no specific temperature limit.
They add that employers have a responsibility for "keeping the temperature at a comfortable level, sometimes known as thermal comfort."
The HSE says there is no limit on high temperatures due to some manufacturing roles requiring constant high temperatures.
Some employers do act and stop their staff from working during high temperatures.
Greenwich council warned this week that some bins may not be collected because of the heatwave.
Employers also have to undertake risk assessments before they actually assign work.
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Within these risk assessments, they will have to weigh up different risks the employee may be exposed to and high temperatures do come under this.
Government guidance states employers should, at a minimum, keep the temperature of the workplace at a comfortable level and provide clean, fresh air.
What other rights do you have?
Although temperature is the main risk, sunburn is another factor employers need to consider.
If your work is primarily outside, like as a construction worker or binman, then your employer should provide you with enough sun cream to cover your shift.
They also need to make sure you have access to plenty of water.
What are trade unions calling for?
The Trade Union Congress has made repeated calls in recent years for a maximum temperature to be introduced in the workplace.
Earlier this week they called for employers to make sure their staff are protected from the heatwave.
They said: "Working in hot weather can lead to dehydration, muscle cramps, rashes, fainting, and – in the most extreme cases – loss of consciousness.
"Outdoor workers are three times more likely to develop skin cancer."
They called on bosses to take steps to keep the temperatures low like relaxing uniform rules, using fans and giving staff flexible hours to avoid the heat of the day.
They called for a law so that employers must attempt to reduce temperatures if they get above 24C and workers feel uncomfortable.
They also called for an absolute working limit of 30C - or 27C for those doing strenuous jobs.
Shadow levelling up secretary Lisa Nandy said Labour had "long called for a maximum temperature and guidance for employers".
She said these guidelines should be in place, not just for extreme heat as the UK is seeing this week, but for industry, such as bakeries, where people work in hot conditions all year round.
"Most employers are crying out for guidance and support from government about what to do and how to respond," Ms Nandy told ITV News.