Elderly people have been warned not to use electric fans in warm weather as they may be damaging to health, a new study suggests.
Researchers have discovered that using electric fans – the sort you would have on the top of your desk to relieve heat and humidity – could actually raise the internal body temperature of those aged 60 and over.
This can increase strain on the heart, the researchers said.
They believe that “age-related impairments in sweating capacity” make fans an ineffective, and even a dangerous way of cooling elderly people down.
The study looked at the physiological responses of a group of older patients between the ages of 60 and 80 in a high-heat, high-humidity environment.
The patients were observed for approximately two hours in a room with the temperature set at 41 degrees Celsius and the humidity level being increased incrementally from 30 per cent to 70 per cent.
The scientists found that heart rates and internal body temperatures rose as the humidity level in the room increased, but those in a room with an electric fan experienced heart rates of up to 10 beats per minute higher.
Lead author Dr Craig Crandall, professor of Internal Medicine at UT Southwestern Medical Centre, US, said: “Although differences were small, the cumulative effect could become clinically important during prolonged heat exposure, such as during extreme heat waves.”
The study concluded that electric fans may be counterproductive for people age 60 and over in high humidity conditions.
Dr Helen Webberley, of the Oxford Online Pharmacy, said the study “makes an interesting and extremely important observation”.
She added: “For the time being, perhaps reducing the fan setting to a low rotation might provide increased levels of comfort while minimising the concerns outlined in the research.”