What the Law says
Temperatures in the workplace (working temperatures) are covered by the Workplace (Health, Safety and Welfare) Regulations 1992, which place a legal obligation on employers to provide a “reasonable” temperature in the workplace. The Approved Code of Practice suggests a minimum temperature in workrooms should normally be at least 16 degrees Celsius – or 13 degrees Celsius if much of the work indoors involves severe physical effort. These temperatures are not absolute legal requirements; the employer’s essential duty is to determine what reasonable comfort will be in the particular circumstances.
A meaningful figure cannot be given at the upper end of the scale. This is because the factors, other than air temperature which determine thermal comfort, i.e. radiant temperature, humidity and air velocity become more significant and the interplay between them more complex as temperatures rise. In addition to the Workplace Regulations, the Management of Health and Safety at Work Regulations 1999 require employers to make a suitable assessment of the risks to the health and safety of their workers, and take action where necessary and where reasonably practicable.
The temperature of the workplace is one of the potential hazards that employers should address to meet their legal obligations. HSE recommends that employers should consult with employees or their representatives, to establish sensible means to cope with high temperatures. In the event of an unresolved dispute, employees may contact their local environmental health office or HSE office for advice on how best to take the matter forward.
(Extract taken from HSE advisory pages)