The UK is forecast to experience a heatwave, with temperatures expected to reach around 37C in parts of the country and up to about 40C in London, prompting red weather warnings from the Met Office. Multiple outlets explain that UK rules do not set a single universal “too hot” temperature at which work must automatically stop. Instead, employers are required to protect workers from heat risk under health and safety law, including undertaking a risk assessment for working conditions. The guidance commonly highlights that where high temperatures create health risks, employers must take reasonable steps such as providing suitable rest breaks, access to drinking water, and appropriate changes to working arrangements. If conditions become unsafe or workers are at risk, employers should reduce or stop activities. The articles also note that advice differs depending on the type of work, whether it is indoor or outdoor, and workers’ vulnerability, so decisions are expected to be situation-specific rather than based solely on the day’s headline temperature.