Electric fans have long been the cheaper go-to when the heat turns up, as they can provide instant cooling relief without ramping up utility bills. But a new study says using fans may not be as safe as it seems.
Researchers from the University of Texas Southwestern Medical Research Center recruited eight adults ages 60 to 80 years old, who were asked to sit for two hours in a compartment similar to a walk-in freezer. The temperature was at 107 degrees, and researchers used a steam generator to increase humidity slowly in the chamber up to 70%. In the first experiment, the participants sat with a 16-inch electric fan. In the second, the fan was absent, Federal News Radio reports.
The researchers found that the fans seemed to make things worse for the elderly.
The participants’ heart rates beat at 10 per minute higher than average, and body temperature came in at half a degree higher with the fans. While these subtle changes may not be immediately significant, they can cause stress to the heart over an extended period, according to senior study author Craig Crandall.
The same experiments were conducted on younger adults, who showed a different response. The fans kept their body temperatures and heart rates down.
The difference in results can be explained by sweat — the body’s way of cooling down to avoid overheating. Electric fans can promote evaporation of sweat by blowing air over a person’s damp skin, Crandall explains. But seniors don’t perspire as much as younger people do, so the natural cooling effect is not as effective, making them more prone to heat-related conditions. For them, Crandall says fans likely just push hot air over their skin.
Matthew Cramer, one of the authors, noted that fans may still be beneficial for the elderly, but in more normal to hot temperatures when less sweat is needed for them to stay cool. The study was unable to determine the upper limit for older people, but Crandall estimates “maybe 100 to 102 degrees.”
The study recommends that older adults should turn to air-conditioning during extreme heat waves. Drinking plenty of fluids will help prevent heat strokes or any similar conditions, as well.
The study was published in the Journal of the American Medical Association.