Due to the different way older people sweat, research shows that using a fan to cool down can actually cause harm to the elderly.
In young people, who sweat in response to a hot environment, a fan causes the evaporation of the sweat away from the skin, taking the heat energy with it. This process effectively brings down core body temperature.
But in older people this does not happen. Despite the fact that an older person might feel cooler in front of a fan, the blowing air actually causes increased heart rate and core body temperature, which can be dangerous. Since the older we get the less we sweat, this causes the body to retain the hot fluids in our bodies. When placed in front of a fan, those hot fluids actually heat up more, not less.
Researchers placed three men and six women in a room set to 108 degrees, and increased the humidity in the room slowly over time. On random days some of the people, whose average age was 68, used a fan, and others did not. Measurements of heart rate, core temperature and sweat loss were taken. The scientists saw that the use of the fan resulted in faster heart rates and increased core temperatures.
Head of the study Dr. Craig Crandall of the University of Texas Southwestern Medical Center, said:
“Although differences were small, their cumulative effect may become clinically important with fan use during more prolonged heat exposure… Fan use elevates sweat loss in young adults. This was not observed in elderly adults, suggesting that age-related impairments in sweating capacity possibly limit the effectiveness of electric fans… Overall, this preliminary study indicates that electric fans may be detrimental for attenuating cardiovascular and thermal strain of elderly adults during heat waves.”