No maximum. Still a duty.
In short: for working in heat, neither the United Kingdom nor Ireland has a legal maximum workplace temperature. In Great Britain, HSE states that heat is classed as a hazard with legal obligations like any other hazard. In Ireland, the HSA guide states that the absence of a maximum does not mean any temperature is acceptable. Both countries give figures for the minimum only.
This is general information, not legal advice; checked October 2026; rules change, see the linked authority.
This page is by Gløde, a clothing brand. We report what the official sources state and link to them. We cover the United Kingdom and Ireland only.
The rules at a glance
| Country | Legal maximum? | Core rule | Figures the source gives | Authority |
|---|---|---|---|---|
| United Kingdom (Great Britain) | No | Workplace (Health, Safety and Welfare) Regulations; Construction (Design and Management) Regulations; Management of Health and Safety at Work Regulations | Minimum only: 16 °C, or 13 °C for rigorous physical work | Health and Safety Executive (HSE) |
| Ireland | No | Safety, Health and Welfare at Work (General Application) Regulations 2007, regulation 7 | Minimum only: 17.5 °C for sedentary office work, 16 °C for other sedentary work | Health and Safety Authority (HSA) |
United Kingdom: what HSE states
No maximum workplace temperature
HSE is clear on the headline: there is no maximum temperature for workplaces. The same page states that heat is classed as a hazard and comes with legal obligations like any other hazard. Source: HSE, Temperature in the workplace: the law.
Three sets of regulations
- The Workplace (Health, Safety and Welfare) Regulations require a reasonable temperature in indoor workplaces.
- The Construction (Design and Management) Regulations require reasonable temperatures for indoor areas of construction sites, and protection from adverse weather for outdoor work.
- The Management of Health and Safety at Work Regulations require employers to assess risks and put controls in place.
A minimum, not a maximum
The Approved Code of Practice suggests that the minimum temperature for working indoors should normally be at least 16 °C. Where much of the work involves rigorous physical effort, it suggests 13 °C. There is no matching figure for heat.
More than air temperature
HSE's heat stress guidance is aimed mainly at workplaces that are hot all year, such as bakeries and foundries. HSE says it also helps in very hot weather. The guidance points out that air temperature is one factor. Work rate, humidity and clothing count as well. Source: HSE, Heat stress.
HSE is the regulator for Great Britain. We did not check the rules for Northern Ireland separately.
Ireland: what the HSA guide states
Regulation 7: a minimum for sedentary work
The Safety, Health and Welfare at Work (General Application) Regulations 2007 deal with temperature in regulation 7. The temperature in a workplace must be appropriate for human beings. For sedentary office work the regulation gives a minimum of 17.5 °C. For other sedentary work it gives 16 °C. Both apply so far as is reasonably practicable, and after the first hour's work.
No maximum, with a caveat
The regulations name no maximum. The HSA guide to the regulations adds a clear caveat: "The fact that a maximum temperature has not been specified in the Regulations does not mean that any temperature is acceptable. At high or uncomfortable temperatures, especially when not caused by temporary weather conditions, a means of cooling should be provided." Source: HSA, Guide to the General Application Regulations 2007: Workplace. The guide dates from 2007.
Indoors and outdoors
The two are not the same. In Great Britain the workplace regulations speak of indoor workplaces. For construction sites, HSE names a separate duty: protection from adverse weather for outdoor work. For Ireland, we checked the regulation on workplace temperature only. For outdoor work there, ask the HSA.
What employers typically do
With no fixed maximum, there is no single number to check against. In Great Britain, HSE points to the risk assessment. Occupational bodies place the measures in a fixed order: technical and organisational first, personal last. In practice, employers typically work through steps like these.
- Take the heat out of the workplace. Ventilation, shade, screens around hot machines.
- Organise the work around the heat. Heavy tasks in the cooler hours, more frequent breaks in a cooler place, drinking water close by.
- Look at clothing. Lighter workwear where the protective function allows it.
- Add personal cooling. Cooling vests come last in that order. They add to the other steps and do not replace them.
Which vest suits which workplace is on our page about the cooling vest for work. More on cooling clothing in general is in our guide to cooling clothing.
And when the workplace is cold
The only figures in these rules are minimums. That is the side Gløde works on. We make heated vests that run on 5 V USB from a power bank, with three heat levels. See our heated vests and the Øney heating insert that goes into a jacket your team already wears. Gløde does not sell cooling clothing.
Frequently asked questions
Is there a maximum workplace temperature in the UK?
No. HSE states that there is no maximum temperature for workplaces. It also states that heat is classed as a hazard and comes with legal obligations like any other hazard.
Is there a maximum workplace temperature in Ireland?
No. The General Application Regulations 2007 give no maximum. The HSA guide adds that this does not mean any temperature is acceptable, and that a means of cooling should be provided at high or uncomfortable temperatures.
What is the minimum workplace temperature?
In Great Britain the Approved Code of Practice suggests at least 16 °C indoors, or 13 °C if much of the work involves rigorous physical effort. In Ireland the regulations give 17.5 °C for sedentary office work and 16 °C for other sedentary work, after the first hour.
Do the rules cover outdoor work?
In Great Britain, HSE names the construction regulations: they require protection from adverse weather for outdoor work on sites. For Ireland, we checked the regulation on workplace temperature only. For outdoor work there, ask the HSA.
Can a cooling vest replace other measures?
No. Occupational bodies list cooling clothing as a personal measure that comes after technical and organisational measures. It adds to them.
All our comparisons and guides →
Gløde — warm the person, not the room.
