As the Health and Safety Manager here at SG World, one question always comes up when the sun shines: 'What is the legal maximum working temperature?'
The short answer is that the UK has no legal upper limit. However, health and safety law requires employers to keep the workplace at a reasonable temperature. While there is no maximum, the HSE does recommend a minimum indoor temperature of 16°C for sedentary work and 13°C for physically demanding work.
You have a duty of care to ensure your staff are safe and comfortable. Managing heat requires a different approach depending on the environment. Here is some practical advice for keeping your team cool and focused, no matter where they are working.
Offices can quickly become stuffy and uncomfortable. Keep blinds and curtains closed before the sun hits the windows to stop the room heating up like a greenhouse. Consider relaxing your company dress code during heatwaves so staff can wear lighter, more breathable clothing.
If your business operations allow it, offer flexible hours. Letting staff start earlier means they can commute and complete their work during the cooler parts of the day.
Machinery generates extra heat, making factory floors incredibly hot. When someone is wearing protective clothing and doing heavy work in hot, humid conditions, their risk of heat stress spikes because sweating is restricted.
Ensure all ventilation systems are working well to reduce humidity. Rotate heavy physical tasks and ensure cold drinking water stations are easily accessible so workers can hydrate without leaving their zones.
Encourage staff to wear lightweight, breathable clothing that covers the arms and legs, along with suitable head protection. Ensure high-factor sunscreen is applied regularly throughout the day and UV-protective eyewear is worn where appropriate.
Remind employees to take regular breaks in shaded areas and to report any symptoms of heat stress, such as dizziness, immediately.
While general ambient heat causes discomfort, combining high temperatures with specific tasks like welding, grinding, or cutting introduces severe situational risks. If your team is carrying out hot work, the ambient temperature can quickly escalate the danger of fires or severe thermal burns.
You must strictly control these activities. Implementing a formal Hot Work Permit to Work ensures that all necessary safety checks are completed, fire watches are assigned, and authorisations are in place before any high-risk tasks begin. This creates a documented audit trail that protects both the worker and the wider site.
Heat stress happens when the body's way of controlling its internal temperature starts to fail. It can result in death if not detected at an early stage. Watch out for these symptoms:
If a colleague shows any of these signs, move them to a cool place immediately, get them water to drink, and seek medical advice.
Share this quick recap with your teams to ensure everyone understands the basics of working in the heat:
Hot weather can be distracting, but routine safety checks must not slip. From daily machinery inspections to managing contractor sign-ins, SG World provides the physical systems you need to maintain a safe and compliant site all year round.