It is usually accepted that people work best at a temperature between 16°C and 24°C, although this can vary depending on the kind of work being done.
The Chartered Institute of Building Services Engineers recommends the following temperatures for different working areas:
Heavy work in factories: 13°C
Light work in factories: 16°C
Hospital wards and shops: 18°C
Offices and dining rooms: 20°C
When the workplace gets too hot it is more than just an issue about comfort. If the temperature goes too high then it can become a health and safety issue.
If people get too hot, they risk dizziness, fainting, or even heat cramps. In very hot conditions the body’s blood temperature rises. If the blood temperature rises above 39 °C, there is a risk of heat stroke or collapse. Delirium or confusion can occur above 41°C. Blood temperatures at this level can prove fatal and even if a worker does recover, they may suffer irreparable organ damage.
However even at lower temperatures heat leads to a loss of concentration and increased tiredness, which means that workers are more likely to put themselves or others at risk. High temperatures mean there is an increase in the likelihood of accidents due to reduced concentration; slippery, sweaty palms as well as an increase of discomfort of some personal protective gear which can result in reduced protection through inappropriate usage or non-usage.
Heat can also aggravate other medical conditions and illnesses such as high blood pressure or heart disease due to increased load on the heart as well as interacting with, or increasing the effect of other workplace hazards. Workers at greater risk of heat stress include those who are 65 years of age or older, are overweight, have heart disease or high blood pressure, or take medications that may be affected by extreme heat.
Scientific studies confirm that indoor temperature can significantly impact on productivity and most performing ‘comfort zone’ lays between 22° C and 25°
When the temperature went above that productivity fell. By 28° C there was already a 5% decrease, and the higher the temperature the lower the output.
The legal position is that an employer must provide a working environment which is, as far as is reasonably practical, safe and without risks to health. In addition, employers have to assess risks and introduce any necessary prevention or control measures.
There is no maximum temperature for workers, although the Workplace (Health,Safety and Welfare) Regulations state the temperature inside workplace buildings must be ‘reasonable’. However there is no consensus over what “reasonable” is and many workers are expected to work in temperatures which are not only uncomfortable, but which could damage their health.
In some sectors it was particularly high including central and local government, education and manufacturing. Often the biggest problem was in post-war buildings with glass windows, skylights etc.
A recent survey of almost 6,000 teachers, school and college leaders and Health and Safety Representatives, found that 94% of respondents reported that they had worked in excessively high temperatures during the summer, with 42% doing so regularly. Clearly this affects the students as well.
In this case the improvement requested was as simple as blinds.
The actual health effects of extreme heat are difficult to quantify or prove as the main short term symptoms, dizziness, headaches and nausea are often also associated with other conditions and those who suffer from the effects of extreme heat rarely report it or record in accident books.
Given the fact that average temperatures are likely to increase over coming years as a result of global warming this is a problem that is likely to increase. It is also a problem that is usually relatively easy to resolve. Simple steps, such as having windows that can be opened, fans, moving staff away from windows or sources of heat or installing ventilation or air-cooling will be effective. If there were a maximum temperature it would also help by ensuring that the issue of temperature was taken into account during the design stage for new buildings or during refurbishment.
Although the Workplace (Health, Safety and Welfare) Regulations only apply to indoor workplaces, employers also have a duty to employers working outside, such as construction or agricultural workers. All employers have a general duty to protect the health and safety of the workforce under the Health and Safety at Work Act, and also to assess and control risks from working in hot temperatures, or exposure to the sun, under the Management of Health and Safety at Work regulations. This includes drivers, where working in a very hot cab can make the person more likely to have an accident.
As stated above this is an issue that is going to exacerbated by the impact of global warming so employers should be thinking ahead about the design of workplaces and replace short term fixes with long term solutions which will benefit workers with better environments and improving productivity and reducing ill health and absenteeism.