Elderly people may experience increased heart rate when electric fans are used during extremely hot weather conditions, suggests a study conducted by UT Southwestern Medical Center heart specialists.
When aged people involved in the study were exposed to temperatures as much as 107 degrees Fahrenheit and high levels of humidity, the body's internal temperature and heart rate further increased when they used electric fans to cool them down.
"Although differences were small, the cumulative effect could become clinically important during prolonged heat exposure, such as during extreme heat waves," said Dr. Craig Crandall, Professor of Internal Medicine at UT Southwestern and with the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas.
As far as young people are concerned, electric fans keep them cool by increasing the rate of evaporation of sweat. As a result, the core temperature and heart rate in young people are not elevated. On the contrary, aged people don't sweat as much as youngsters do and so using electric fans have an opposite effect on the group.
To be able to understand the impact of electric fans on elderly during extreme heat, the researchers exposed a small group of people aged between 60 and 80 to varied temperatures and humidity. The study subjects, six women and three men, were dressed in bras and shorts respectively. The participants were made to remain in a room with the temperature measruing 107 degrees Fahrenheit for about two hours. Then the humidity and temperature levels were increased gradually from 30 to 70 percent.
Eventually, both the core temperature and heart rate increased in all the nine study participants. The experiment was carried out in settings both with and without fan. When participants stayed in settings fitted with electric fans, their core temperature and heart rate increased by 0.5 degrees Fahrenheit and 10 beats per minute respectively.
Crandall said that he is bothered that the study findings might stop people from using electric fans. The research deals with the use of electric fans in extreme heat and not during regular weather, he clarified.
According to the researchers, though electric fans don't help during heat waves they can still be used in less extreme conditions. Crandall also suggested that older people who don't have access to air conditioners should stay as hydrated as possible in hot weather. They can also try to stay in community halls, shopping malls or at friends' or relatives' place where they have access to air conditioners.
The study was published in The Journal of the American Medical Association on Sept. 6.
Photo: Toshiyuki IMAI | Flickr