As a potential 37°C heatwave approaches the UK this August, employers are reminded of their duty of care to ensure a safe working environment. While there is no specific legal maximum temperature for offices, the Health and Safety Executive (HSE) requires employers to maintain a “reasonable” temperature and ensure staff have access to fresh air and drinking water.
New insights from water experts at Culligan highlight the critical role of hydration. The research found that over half of British workers (52%) now take a reusable water bottle to work and refill it an average of three times a day, which aligns with the recommended daily water intake. However, a surprising 62% of workers say they do not set daily hydration goals.
Dehydration can have a significant impact on performance and safety. A mere 1% drop in hydration levels can lead to a 5% decline in cognitive function, while a 2% reduction can cause short-term memory loss and difficulty with mathematical tasks.
According to Simon Phillips, a business transformation expert, providing clean, safe drinking water is a non-negotiable for any workplace.
“Every single workplace should provide clean, safe drinking water. This isn’t a nice-to-have; it’s a fundamental human need and basic duty of care as dehydration affects everything, from decision-making to mood and on to physical performance.”
Phillips notes that in hot environments, performance “drops off a cliff.” This is not just about productivity; it is a serious health and safety concern that can lead to accidents and injuries in both office and physical labour environments. He stresses that one water cooler for 50 people is inadequate; people need easy, constant access.
Phillips suggests that employers approach heatwave safety using the LACE framework:
- Listening: Are you hearing when people say they are struggling with the heat, or dismissing it as “moaning”?
- Accountability: Taking responsibility for safe, comfortable working conditions is not optional.
- Collaboration: Work with your teams to find solutions, as they know what they need.
- Empathy: Understand that heat affects people differently, and what might be fine for you could be debilitating for someone else.
In essence, looking after employees during hot weather is not just about avoiding legal issues. It is about human decency and creating a workplace where people can genuinely thrive, whatever the weather.

