Last edited 25 Jul 2019

Cold stress

UK law does not prescribe maximum or minimum temperatures. Temperatures in the workplace are governed by the Workplace (Health, Safety and Welfare) Regulations 1992, but this simply obliges employers to provide a ‘reasonable’ temperature.

The approved code of practice ‘Workplace health, safety and welfare’ provides some guidance, suggesting a minimum temperature of 16 degrees Celsius, or 13 degrees Celsius if work involves severe physical effort. There are no guidelines for maximum temperatures, although Health and Safety Executive (HSE) guidance used to suggest 30 degrees Celsius might be a maximum depending on activities.

However, there may be particular risks from exposure to high or low temperatures. Where thermal conditions mean the measures people’s bodies uses to regulate internal temperature begin to fail, this can be described as ‘thermal stress’, such as heat stress and cold stress. If there is a risk of thermal stress, this must be assessed and managed. In the case of cold stress, this might include conditions that are below 12 degrees Celsius.

The HSE has developed a ‘Controlling the risks in the workplace’ method to help employers in the assessment of thermal stress conditions:

Step 1 : Identify the hazards.
Step 2 : Decide who is at risk.
Step 3 : Evaluate the risks.
Step 4 : Record findings.
Step 5 : Review assessment

Cold conditions may be a normal part of a person’s day, for which they are well prepared, or may be an unusual situation resulting from extreme weather or from unforeseen circumstances such as failure of heating equipment. Cold stress can be relatively mild, or it can be extremely serious resulting in hypothermia, frostbite, or even death. Some people may be more susceptible to cold stress than others.

Symptoms might include:

Shivering (or stopping shivering).
Tiredness, poor coordination or confusion which can lead to accidents.
Discolouration of the skin or itching.
Dilated pupils.
Reduced blood flow, numbness, swelling, tingling or cramps.
Blisters.
Slowed pulse or breathing.
Loss of consciousness.

Avoidance measures might include:

Portable heaters.
Minimising exposure to cold areas or cold products.
Providing breaks.
Reducing cold draughts.
Insulating floors.
Providing personal protective equipment such as protective clothing, special footwear and so on.

The HSE advises that the following British Standards are referred to as a basis from which to formulate a risk assessment strategy and to start managing cold stress:

BS EN 511: Specification for protective gloves against cold.
ISO 13732-3 Ergonomics of the thermal environment - Touching of cold surfaces Part 3. Ergonomics data and guidance for application.
BS 7915: 1998 Ergonomics of the thermal environment : Guide to design and evaluation of working practices for cold indoor environments.
ISO 11079 Evaluation of cold environments - Determination of required clothing insulation (IREQ)
ISO 15743 Ergonomics of the thermal environment - cold workplaces - risk assessment and management

Ref HSE: Cold stress.

HSE suggest that additional standards may need to be referred to depending on operational circumstances.

NB In November 2016, construction union UCATT wrote to major house builders proposing extreme weather health and safety guidelines. UCATT General Secretary Brian Rye said, “It’s a complete indictment of an industry that has temperature guidelines to safeguard materials but none whatsoever for the workers. This must now change. We have written to the NHBC to ask them to inject some humanity into the industry and provide clear temperature and extreme weather guidelines for constructors to apply to workers."