Heatwaves in England: What are Employers’ legal duties?

Temperatures are currently reaching over 35 degrees for a number of days, with the UK Health & Safety Agency and Met Office announcing red heat health alerts across a large part of England and Wales. 

With temperatures rising across England and heatwaves becoming more frequent, Employers are increasingly being required to consider how hot weather impacts the workplace. Recent guidance from the Health and Safety Executive (HSE) reinforces that extreme heat is a health and safety issue that must be actively managed.

• No maximum workplace temperature
  • There is currently no legal upper temperature limit in the UK for workplaces.
  • There is a minimum working temperature of 16 degree.
• “Reasonable” working conditions remain the test
  • Employers must maintain a reasonable temperature in indoor workplaces under the Workplace (Health, Safety and Welfare) Regulations 1992.
  • What is “reasonable” depends on the nature of the work and the working environment.
• Overarching duty of care
  • Employers must ensure, so far as reasonably practicable, the health, safety and welfare of Employees, including risks arising from extreme heat.
• Risk assessment obligations
  • Employers must assess risks (including heat stress) and implement appropriate control measures under the Management of Health and Safety at Work Regulations.
• Heat is a recognised workplace hazard
  • The HSE makes clear that excessive heat should be treated like any other hazard requiring mitigation. 

In practice, Employers are expected to take proportionate and sensible steps, including:

• Undertaking risk assessments
  • Identify heat-related risks, particularly for outdoor or physically demanding roles.
• Providing a safe working environment
  • Ensure adequate ventilation, airflow and where possible, cooling measures such as fans and air conditioning units.
• Hydration and welfare
  • Provide access to drinking water, which is a legal requirement.
• Adjusting working arrangements
  • Consider:
  • flexible working hours
  • remote working
  • rescheduling physically demanding tasks to cooler times of day
• Allowing rest and recovery
  • Offer additional breaks, particularly in shaded or cooler areas.
• Dress code flexibility
  • Relax formal dress requirements and dress down days where appropriate, subject to health and safety needs (e.g. PPE). 

• Vulnerable employees
  • Employers must give particular consideration to:
    • pregnant workers
    • those with medical conditions such a COPD and arthritis
    • Employees taking medication affected by heat
• Outdoor workers
  • Additional protections may be required, including shade, protective clothing and altered working patterns.
• Right to refuse unsafe work
  • Employees may be protected if they refuse to work where they have a reasonable belief of serious and imminent danger (subject to specific facts). 

• There is no automatic “too hot to work” threshold, but that does not remove Employer responsibility.
• The focus is on risk assessment and proactive management, not fixed temperature limits.
• Employers who fail to take reasonable steps risk:
  • Health and Safety breaches
  • Personal Injury claims
  • Potential Constructive Dismissal arguments in extreme cases (opinion based on general legal principles).

Heatwaves present a growing workplace risk. While UK law does not prescribe a maximum temperature, it is clear that employers must treat extreme heat as a foreseeable and manageable hazard. Taking sensible, documented steps now will not only ensure compliance but also protect employee wellbeing and productivity.

Practical steps to make the working day more comfortable for Employees will also have the added benefit of maintain productivity as well as creating a culture of feeling cared for and considered.