The heart rate and inside temperature of senior citizens subjected to 107 degree Fahrenheit temperatures and increasing humidity levels climbed even greater when they attempted to cool down off with fans– rather of falling as expected, according to study findings reported in JAMA.
” Although distinctions were small, the collective effect could become medically important during extended heat exposure, such as during severe 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, a joint operation of Texas Health Presbyterian Hospital Dallas and UT Southwestern.
” We understand that fans keep younger adults much cooler by boosting the evaporation of sweat,” Dr. Crandall said. “We surmise that age-related problems in perspiration ability make fans an inadequate means of cooling for the elderly during extremely hot days, and may, in reality, increase cardiac and thermal stress.”
Not surprisingly, both heart rate and internal body temperature rose as the humidity level in the room rose. The eight individuals in the study were tested under those conditions without a fan and, on a separate occasion, with an electric fan. Unexpectedly, the participants’ heart rates were 10 beats per minute higher and their internal temperatures 0.5 degrees Fahrenheit greater when a fan was part of the experimental environment.
These results suggest that fan use may be counterproductive for seniors during heat waves, the investigators propose that fan use may still be beneficial under less extreme environmental conditions, though this needs to be confirmed.
During intense heat waves seniors who do not live in an air-conditioned home must maintain hydration while seeking an air-conditioned environment such as a family member or friend’s home, a community center, or a shopping mall, Dr. Crandall said