Can you legally leave work if it is too hot?
Your own health will also be important and may mean that your employer owes a special duty of care to you, provided you have reported any relevant health concerns. As always, open and respectful conversations are essential and if for some reason you don’t feel able to have these conversations with your supervisor or employer yourself, there should be a way that you can. an advocate can speak on your behalf.
The situation vis-à-vis your husband and working outside as a letter carrier is the same in that there is no maximum temperature when he has the legal right to stop working, but just like you, his employers, must be respectful of the role he has and the particular risks that this brings.
For example, outside workers are at risk for dehydration and skin cancer. HSE claims that 4,500 skin cancers occur each year as a result of working outdoors. My personal view is that sunscreen should be provided to outdoor workers.
Again, this is not a black letter law, but it is an HSE regulation since 1992 which provides that employees are provided with appropriate personal protective equipment (PPE) and I think for those who work in the field. outdoors, sunscreen is PPE. This is both humane and from a legal standpoint, it will help fend off a future claim from an employee who, sadly, is diagnosed with skin cancer.
Other measures to mitigate damage to outdoor workers include determining whether the work can be done earlier or later in the day, thus avoiding the midday sun. Also, a casual dress code in summer is good practice and indeed I suspect Royal Mail offers alternative uniforms for warmer days.
In summary, you should continue to work in the heat, even if the tenor of your questions indicates that you are okay with it. What you can expect are steps to keep you comfortable. So keep up the good work, enjoy the sun and ask your boss for ice cream.