Heat stress - Revision history

Designing Buildings at 10:04, 24 June 2026

2026-06-24T10:04:16Z

← Older revision		Revision as of 10:04, 24 June 2026
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		+	[[File:Heat stress summary.png]]
		+
	= Introduction =		= Introduction =

Designing Buildings at 09:58, 24 June 2026

2026-06-24T09:58:35Z

← Older revision		Revision as of 09:58, 24 June 2026
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−	~~Temperatures in the workplace are governed by the Workplace (Health, Safety and Welfare) Regulations 1992, which oblige employers to provide a reasonable temperature in the workplace.~~	+	= Introduction =

−	~~The Approved Code of Practice (Workplace health, safety and welfare.~~ Workplace (Health, Safety and Welfare) Regulations 1992. ~~Approved Code of Practice ) suggests~~ a minimum temperature ~~of 16 °C~~, ~~or 13°C if work involves severe physical effort. However, these are only guidelines, and the complexity of temperatures means there~~ is ~~no maximum guideline temperature~~.	+	Temperatures in the workplace are governed by the Workplace (Health, Safety and Welfare) Regulations 1992, which require employers to maintain a reasonable indoor temperature in the workplace. The regulations do not specify a maximum or minimum temperature, but instead set a general duty to ensure thermal comfort so far as is reasonably practicable.

−	The ~~Health and Safety Executive~~ (~~HSE~~) ~~did previously define thermal comfort~~ in the ~~workplace~~, ~~as '…roughly between~~ 13°C ~~and 30°C, with acceptable temperatures for more strenuous~~ work ~~activities concentrated towards the bottom end of the range, and more sedentary activities towards the higher end~~.'	+	The associated Approved Code of Practice (ACOP) advises that, in most indoor workplaces, the temperature should normally be at least 16°C, or 13°C where work involves severe physical effort. These figures are guidance rather than legal limits.

−	~~However, thermal comfort, particularly at higher temperatures cannot sensibly be reduced to a single measure~~. ~~It is dependent on a range~~ of ~~environmental factors in addition to air~~ temperature, ~~such as; air velocity~~, ~~radiant temperature, relative humidity~~ and ~~the uniformity of conditions. It also depends on~~ personal factors ~~such as; clothing, metabolic heat, state of health, aclimatisation, expectations, and even access to food and drink. See thermal comfort for more information~~.	+	There is no statutory maximum workplace temperature in the UK. This reflects the complexity of thermal environments and the fact that acceptable temperature varies depending on activity, environment, and personal factors.

−	~~Heat stress is a form of overheating that~~ the ~~occupants of a building may experience when the measures their body uses~~ to ~~regulate internal temperature begin~~ to ~~fail~~. ~~This can occur for example in buildings where an industrial process is being carried out~~, ~~such as; smelting, brick-firing, cooking~~ and so on.	+	Historically, the Health and Safety Executive (HSE) described thermal comfort in broad terms (often cited as approximately 13°C to 30°C), with lower temperatures suited to more physically demanding work and higher temperatures to sedentary tasks. However, HSE guidance now places less emphasis on fixed temperature ranges and more on risk assessment and environmental heat stress indicators.

−	~~Heat stress is~~ a ~~personal condition; some occupants may experience heat stress whilst others may not. Where humidity is high~~, or ~~occupants are wearing protective clothing that cannot be adjusted or removed~~, ~~the body may be unable~~ to ~~lose heat~~ through ~~the evaporation of sweat~~ and ~~so individuals may begin to experience elevated deep-body temperature~~, ~~excessive sweating and increased heart rate~~.	+	In 2006, the Trades Union Congress (TUC) suggested a maximum workplace temperature of 30°C, or 27°C for strenuous work. More recently, similar thresholds have been referenced in political discussions and policy proposals, including Labour Party proposals in 2019 to explore enforceable maximum workplace temperatures through a proposed Royal Commission on Health and Safety at Work. However, these remain policy proposals rather than statutory requirements.

−	~~This in turn can lead to:~~	+	= Thermal comfort =

−	* Dehydration.	+	Thermal comfort cannot be determined by air temperature alone.
−	* Headache, difficulty concentrating and confusion.	+
−	* Muscle cramp.	+
−	* Heat rash.	+
−	* Fatigue.	+
−	* Giddiness and fainting.	+
−	* Nausea.	+
−	* Convulsions.	+

−	~~Ultimately, if it is allowed to persist,~~ heat stress ~~can cause death~~.	+	The HSE recognises the Wet Bulb Globe Temperature (WBGT) index as a useful method for assessing heat stress risk in occupational environments. WBGT incorporates:

−	The Workplace Regulations, the Management of Health and Safety at Work Regulations 1999 require that employers assess the risks to the health and safety of their workers, and take action where necessary and reasonably practicable. Measures taken to reduce the risk of heat ~~stress might include:~~	+	* natural wet-bulb temperature
		+	* globe temperature (radiant heat)
		+	* air temperature

−	* Changes to the environment or to processes to reduce activity or exposure to heat.	+	However, thermal comfort is influenced by a combination of environmental and personal factors, including:
−	* Reducing the length of ~~exposure~~ and ~~allowing acclimatisation.~~	+
−	* Giving access to water.	+
−	* Using specialist personal ~~protective equipment.~~	+
−	* Training.	+
−	* Assessing and monitoring health.	+

−	~~The Health and Safety Executive suggest that wet bulb globe temperature can be used as a measure of likely heat stress. It includes components of natural wet-bulb~~ temperature (~~tnw~~)~~, globe~~ temperature (tg) and ~~air temperature (ta). See wet bulb globe temperature for more information.~~	+	* air temperature
		+	* air movement (velocity)
		+	* radiant temperature
		+	* relative humidity
		+	* clothing insulation
		+	* metabolic rate (activity level)
		+	* acclimatisation
		+	* health status and individual tolerance
		+	* access to hydration

−	~~NB In 2006~~, ~~the Trades Union Congress (TUC) stated that it believed a maximum temperature of 30ºC~~ should be ~~set, or 27ºC for those doing strenuous work. In July 2019, the Labour party proposed the same maximum workplace~~ temperature ~~of 30ºC, or 27ºC for those doing strenuous work. They tasked a proposed Royal Commission on Health and Safety at Work with bringing forward proposals~~.	+	Because of this complexity, thermal comfort should be assessed using a holistic approach rather than a single temperature value.

−	= Related articles on Designing Buildings ~~Wiki~~ =	+	= Heat stress =
		+
		+	Heat stress occurs when the body’s ability to regulate its internal temperature is overwhelmed. This can lead to a rise in core body temperature and associated physiological strain. It is more likely in environments involving high heat loads, such as industrial processes including smelting, foundries, brick firing, kitchens, or poorly ventilated plant rooms and roof spaces in hot weather. Where humidity is high or where personal protective equipment (PPE) restricts evaporation of sweat, the body’s ability to cool itself is reduced, increasing risk.
		+
		+	Heat stress is a personal physiological response, meaning that individuals exposed to the same conditions may experience different effects depending on clothing, workload, hydration, and health status.
		+
		+	Symptoms may include:
		+
		+	* dehydration
		+	* headache, reduced concentration, and confusion
		+	* muscle cramps
		+	* heat rash
		+	* fatigue
		+	* dizziness or fainting
		+	* nausea
		+	* in severe cases, convulsions
		+
		+	If untreated, severe heat stress can lead to heat exhaustion or heat stroke, which can be fatal.
		+
		+	= Employer duties and risk control =
		+
		+	Under the Management of Health and Safety at Work Regulations 1999, employers are required to assess risks to health and safety, including those arising from heat, and implement reasonably practicable control measures.
		+
		+	Typical mitigation measures include:
		+
		+	* reducing heat exposure through engineering or process changes
		+	* improving ventilation or cooling
		+	* limiting duration of exposure and introducing rest breaks
		+	* allowing time for acclimatisation
		+	* providing adequate drinking water
		+	* adjusting workload and work rate where possible
		+	* using suitable PPE that balances protection with heat burden
		+	* training workers to recognise symptoms of heat stress
		+	* monitoring workplace conditions and worker health where appropriate
		+
		+	= Related articles on Designing Buildings =

	* BREEAM Thermal comfort.		* BREEAM Thermal comfort.

Designing Buildings at 07:47, 10 November 2020

2020-11-10T07:47:21Z

← Older revision		Revision as of 07:47, 10 November 2020
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	* Wet bulb temperature.		* Wet bulb temperature.

−	[[Category:~~Health_and_safety_/_CDM~~]] [[Category:~~Standards_~~/~~_measurements~~]] [[Category:~~DCN_Standard~~]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Health_and_safety_/_CDM]] [[Category:Standards_/_measurements]]

Editor at 18:04, 26 May 2020

2020-05-26T18:04:01Z

← Older revision		Revision as of 18:04, 26 May 2020
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	* Relative humidity.		* Relative humidity.
	* Temperature.		* Temperature.
		+	* Tempering heating.
	* Thermal comfort.		* Thermal comfort.
	* Types of heating system.		* Types of heating system.
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	* Wet bulb temperature.		* Wet bulb temperature.

−	[[Category:Health_and_safety_/_CDM]] [[Category:Standards_/_measurements]]	+	[[Category:Health_and_safety_/_CDM]] [[Category:Standards_/_measurements]] [[Category:DCN_Standard]]

Designing Buildings at 10:30, 23 August 2019

2019-08-23T10:30:17Z

← Older revision		Revision as of 10:30, 23 August 2019
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	* Globe temperature.		* Globe temperature.
	* ‎Maximum and minimum workplace temperatures.		* ‎Maximum and minimum workplace temperatures.
		+	* Occupational health.
	* Overheating.		* Overheating.
	* Personal protective equipment.		* Personal protective equipment.

Designing Buildings at 09:25, 25 July 2019

2019-07-25T09:25:18Z

← Older revision		Revision as of 09:25, 25 July 2019
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	* Cold stress.		* Cold stress.
	* Construction work in hot weather.		* Construction work in hot weather.
−	* Draught proofing.
	* Dry bulb temperature.		* Dry bulb temperature.
	* Globe temperature.		* Globe temperature.
−	* ~~Health~~ and ~~safety.~~	+	* ‎Maximum and minimum workplace temperatures.
−	* Heating.	+
−	* Method statement.	+
	* Overheating.		* Overheating.
	* Personal protective equipment.		* Personal protective equipment.

Designing Buildings at 08:18, 25 July 2019

2019-07-25T08:18:50Z

← Older revision		Revision as of 08:18, 25 July 2019
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	The Health and Safety Executive suggest that wet bulb globe temperature can be used as a measure of likely heat stress. It includes components of natural wet-bulb temperature (tnw), globe temperature (tg) and air temperature (ta). See wet bulb globe temperature for more information.		The Health and Safety Executive suggest that wet bulb globe temperature can be used as a measure of likely heat stress. It includes components of natural wet-bulb temperature (tnw), globe temperature (tg) and air temperature (ta). See wet bulb globe temperature for more information.

−	~~= Find out more =~~	+	NB In 2006, the Trades Union Congress (TUC) stated that it believed a maximum temperature of 30ºC should be set, or 27ºC for those doing strenuous work. In July 2019, the Labour party proposed the same maximum workplace temperature of 30ºC, or 27ºC for those doing strenuous work. They tasked a proposed Royal Commission on Health and Safety at Work with bringing forward proposals.

−	=== Related articles on Designing Buildings Wiki ===	+	= Related articles on Designing Buildings Wiki =

	* BREEAM Thermal comfort.		* BREEAM Thermal comfort.

Editor at 15:13, 20 April 2018

2018-04-20T15:13:58Z

← Older revision		Revision as of 15:13, 20 April 2018
Line 42:		Line 42:
	* Cold stress.		* Cold stress.
	* Construction work in hot weather.		* Construction work in hot weather.
		+	* Draught proofing.
	* Dry bulb temperature.		* Dry bulb temperature.
	* Globe temperature.		* Globe temperature.

Designing Buildings at 14:12, 26 March 2018

2018-03-26T14:12:07Z

← Older revision		Revision as of 14:12, 26 March 2018
Line 39:		Line 39:
	=== Related articles on Designing Buildings Wiki ===		=== Related articles on Designing Buildings Wiki ===

		+	* BREEAM Thermal comfort.
	* Cold stress.		* Cold stress.
	* Construction work in hot weather.		* Construction work in hot weather.
	* Dry bulb temperature.		* Dry bulb temperature.
−	* Ergonomics in construction.
	* Globe temperature.		* Globe temperature.
	* Health and safety.		* Health and safety.

Editor at 16:12, 8 February 2018

2018-02-08T16:12:57Z

← Older revision		Revision as of 16:12, 8 February 2018
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	The Approved Code of Practice (Workplace health, safety and welfare. Workplace (Health, Safety and Welfare) Regulations 1992. Approved Code of Practice ) suggests a minimum temperature of 16 °C, or 13°C if work involves severe physical effort. However, these are only guidelines, and the complexity of temperatures means there is no maximum guideline temperature.		The Approved Code of Practice (Workplace health, safety and welfare. Workplace (Health, Safety and Welfare) Regulations 1992. Approved Code of Practice ) suggests a minimum temperature of 16 °C, or 13°C if work involves severe physical effort. However, these are only guidelines, and the complexity of temperatures means there is no maximum guideline temperature.

−	The Health and Safety Executive (HSE) did previously define thermal comfort in the workplace, as '…roughly between 13°C and 30°C, with acceptable temperatures for more strenuous work activities concentrated towards the bottom end of the range, and more sedentary activities towards the higher end.' However, thermal comfort, particularly at higher temperatures cannot sensibly be reduced to a single measure. It is dependent on a range of environmental factors in addition to air temperature, such as; air velocity, radiant temperature, relative humidity and the uniformity of conditions. It also depends on personal factors such as; clothing, metabolic heat, state of health, ~~acclimatisation~~, expectations, and even access to food and drink. See thermal comfort for more information.	+	The Health and Safety Executive (HSE) did previously define thermal comfort in the workplace, as '…roughly between 13°C and 30°C, with acceptable temperatures for more strenuous work activities concentrated towards the bottom end of the range, and more sedentary activities towards the higher end.'
		+
		+	However, thermal comfort, particularly at higher temperatures cannot sensibly be reduced to a single measure. It is dependent on a range of environmental factors in addition to air temperature, such as; air velocity, radiant temperature, relative humidity and the uniformity of conditions. It also depends on personal factors such as; clothing, metabolic heat, state of health, aclimatisation, expectations, and even access to food and drink. See thermal comfort for more information.

	Heat stress is a form of overheating that the occupants of a building may experience when the measures their body uses to regulate internal temperature begin to fail. This can occur for example in buildings where an industrial process is being carried out, such as; smelting, brick-firing, cooking and so on.		Heat stress is a form of overheating that the occupants of a building may experience when the measures their body uses to regulate internal temperature begin to fail. This can occur for example in buildings where an industrial process is being carried out, such as; smelting, brick-firing, cooking and so on.
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	* Temperature.		* Temperature.
	* Thermal comfort.		* Thermal comfort.
		+	* Types of heating system.
	* Wet bulb globe temperature.		* Wet bulb globe temperature.
	* Wet bulb temperature.		* Wet bulb temperature.

	[[Category:Health_and_safety_/_CDM]] [[Category:Standards_/_measurements]]		[[Category:Health_and_safety_/_CDM]] [[Category:Standards_/_measurements]]