Workers went back to the office on Monday (June 19) after a scorching hot weekend.
But temperatures remain high - with temperatures hitting 32 °C on Monday, with similar temperatures also predicted for Tuesday.
The National Trade Union Centre (TUC) previously gave advice to workers who are struggling with soaring temperatures in the workplace.
"When the workplace gets too hot it is more than just an issue about comfort," the TUC said.
"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."
What rights do you have?
The TUC wants to make it illegal to keep people at work indoors if the temperature is above 30°C and protection in place for people working outside or driving for a living too.
But before you get too excited and start checking whether your workplace is above 30°C, this law isn't in place yet.
However, there is some good news - you CAN leave an office that's too hot, but there isn't any official max temperature as yet.
"An employer must provide a working environment which is, as far as is reasonably practical, safe and without risks to health. In addition, employers have to assess risks and introduce any necessary prevention or control measures," the TUC explains.
Are there any frameworks in place for when things get uncomfortable?
The Health and Safety Executive, in charge of providing the regulatory frameworks for workplace health and safety, has a few tips for what to do in that stuffy office of yours.
Its says: "A meaningful maximum figure cannot be given due to the high temperatures found in, for example, glass works or foundries.
"The Workplace (Health, Safety and Welfare) Regulations 1992 lay down particular requirements for most aspects of the working environment.
"Regulation 7 deals specifically with the temperature in indoor workplaces and states that ‘during working hours, the temperature in all workplaces inside buildings shall be reasonable'.
"However, the application of the regulation depends on the nature of the workplace, such as a bakery, a cold store, an office, a warehouse."
Employers also have to provide “clean, fresh air” as well as keep temperatures at a comfortable level.
Right, so how hot does it have to be before I can complain?
The fact that there is no official limit may work in your favour here, as you can get action taken at whatever temperature so long as people think it is uncomfortable to work in.
"If a significant number of employees are complaining about thermal discomfort, your employer should carry out a risk assessment, and act on the results of that assessment," the HSE explains.
If you're a more vulnerable employee – for example have a thyroid imbalance or are undergoing the menopause, or need to wear protective equipment at work so can't take of layers - that also has to be taken into account.
If enough people tell your boss that they're uncomfortable, they have to take action, which could result in you getting off work!