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With the Met Office issuing its first “Red Extreme” and “danger to life” heat warning for Monday (18) and Tuesday (19), and temperatures in some places reaching 40°C, the TUC is calling on bosses to make sure workers are protected from the sun and the heat.

Workers should be aware that employers have a duty of care, and a legal obligation to protect their health, ensuring working temperatures are reasonable, comfortable and safe.

These temperatures present a serious risk of sunstroke, heat stress and sunburn. Working in hot weather can also lead to dehydration, tiredness, muscle cramps, rashes, fainting, and – in the most extreme cases – loss of consciousness.

If a colleague becomes confused or agitated, loses consciousness, or is unable to drink, seek urgent medical attention.

Outdoor work

Employers must work with union health and safety reps to introduce measures to protect their staff who work outdoors when the temperatures rise, including:

  • Avoiding outside tasks between 11am – 3pm when temperatures, and risks, are highest.
  • Provide sunscreen and advice on the need for protection, available in other languages for migrant workers where relevant.
  • Allow staff to take plenty of breaks and provide a supply of drinking water.
  • Provide canopies or covering over open areas and shaded areas for breaks.
  • Provide lightweight protective clothing, including hats.


The heat can be dangerous for workers whose jobs involve driving, as any driver suffering from fatigue is a risk to themselves and other people. vehicles used for long journeys should be temporarily taken out of use if they cannot sustain a reasonable temperature, e.g. they do not have air conditioning.

Indoor work

Indoor workplaces could also become dangerously hot, and TUC advice is that nobody should be working indoors where temperatures exceed 30°C. At 24°C employers must take action to cool the air, and other measures including:

  • Using fans or other mechanisms to cool the air, as well as adequate ventilation.
  • Relaxing dress codes and uniform policies.
  • Allowing rest breaks and adjusting shifts to avoid travelling in peak heat.
  • Moving workspaces away from windows and other heat sources, using blinds to block out sun.
  • Providing cool drinking water.

Maximum temperatures

Employers must ensure working temperatures are “reasonable”. The TUC believes employers must take action when indoor temperatures exceed 24°C, with 30°C being an absolute maximum – certainly no longer “reasonable”.

Guidance elsewhere states:

  • In the US regulations say working temperatures should not go beyond 24°C
  • Spain has strict guidelines on working temperature: it must not go beyond 27°C indoors or 25°C for physical activity.
  • In Germany, 26°C is generally considered the maximum for indoor work.
  • In China, when temperatures reach 37°C outdoor work is banned during the hottest three hours of the day, and at 40°C it must stop altogether.
  • In the UAE, outdoor work is banned entirely between the hours of 12:30 and 15:00 when it’s hottest.


Personal Protective Equipment is defined as “all equipment which is intended to be worn or held by a person at work and which protects him against one or more risks to his health or safety, and any addition or accessory designed to meet that objective.”

Sunburn and complications resulting from UVA radiation are a known risk to health, and outdoor workers are already three times more likely to develop skin cancer than the general working population. Sunscreen creates a barrier between the worker and the risk, and as such should be considered personal protective equipment.

Employers should provide sunscreen with a factor of at least 30, made available free of charge to all workers whose work involves outdoor activities.

Excuses such as allergies should be dismissed. Workers can be allergic to any number of ingredients, fabrics or materials used in equipment, for example hand sanitsier.

Refusal by a worker to wear PPE on that basis is valid. Refusal by the employer to supply it to the wider workforce is not.

The right to refuse

Section 44 of the Employment Rights Act 1996 provides workers protection from detriment (i.e. dismissal, disciplinary or a pay cut) if they withdraw from and to refuse to return to a workplace that is unsafe. Workers are entitled to remain away from the workplace if – in their opinion – the prevailing circumstances represent a real risk of “serious and imminent danger” which they could not be expected to avert. The TUC says workers should seek advice from their union before using their rights under Section 44.

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