The UK applies health and safety guidance to help protect workers from excessive heat, but there is no single, universally enforced “maximum working temperature” across all workplaces. Instead, heat protection is addressed through workplace risk assessments under UK health and safety law. Government guidance sets out factors that employers must consider, including the temperature, humidity, air movement, direct sunlight, the nature of the work, and whether workers have access to rest and drinking water. The guidance also encourages employers to plan measures before conditions become dangerous, such as allowing breaks, providing suitable ventilation or cooling where feasible, and adjusting work schedules when temperatures rise. Workers are generally entitled to safe working conditions, and employers must take reasonable steps to manage thermal risks. Enforcement and specific limits can vary depending on the workplace, the type of work, and how risks are assessed. The overall approach is therefore risk-based: employers must identify hazards from heat and implement controls to reduce the risk to staff, particularly during periods of hot weather.