Are you finding it difficult to work in this heat?
If you are, health and safety legislation says workplace temperatures should be “reasonable”. Workplace temperature is a potential hazard employers should address to meet their legal obligations.
You can ask your employer to carry out a risk assessment because of the heat. All workers should be consulted and the results of the assessment should be shared with workers.
If you are unhappy with how your employer is managing the heat, contact UVW and consider taking out a collective grievance.
If there is still a serious or imminent danger, you and your colleagues may have the right to leave work depending on the specific circumstances. Consult UVW and get support.
UVW could advise you on whether you can invoke Section 44 of the Employment Act 1996. You should not invoke it by yourself. Nobody should place themselves in danger for the sake of work!