But can you ask your boss to go home if it's unbearable?
The simple answer: Not yet as there is no temperature limit set work UK workplaces. But there is some hope for those struggling...
The Health and Safety Executive (HSE), which is in charge of guidelines like this, says it's not practical to bring in such a rule, because some places of work need to have very high temperatures - glass foundries, for example.
But The Workplace (Health, Safety and Welfare) Regulations 1992, does have a rule which states: "During working hours, the temperature in all workplaces inside buildings shall be reasonable."
Reasonable? It leaves a lot of leeway for those in charge to make a decision but it does pose a question.
The HSE guidelines do say that if a 'significant' number of employees complain about the heat then the employer should carry out a risk assessment. There's strength in numbers, it seems.
'Irreparable organ damage'
The Trades Union Congress (TUC) would like maximum and minimum temperatures introduced.
The TUC says: "Trade unions want to see a legal maximum temperature for indoor work of 30°C (27°C for those doing strenuous work), so that employers and workers know when action must be taken. It should be stressed that this is intended as an absolute maximum rather than an indication that regular indoor work at just below 30°C would be acceptable.
"There should also be a legal duty on employers to protect outside workers by providing sun protection, water, and to organise work so that employees are not outside during the hottest part of the day."
The TUC adds that working in hot conditions isn't just uncomfortable, but that it can actually be very dangerous. It says: "If the temperature goes too high then it can become a health and safety issue. If people get too hot, they risk dizziness, fainting, or even heat cramps.
"In very hot conditions the body's blood temperature rises. If the blood temperature rises above 39°C, there is a risk of heat stroke or collapse. Delirium or confusion can occur above 41°C.
"Blood temperatures at this level can prove fatal and even if a worker does recover, they may suffer irreparable organ damage."