Not really. If you’re out in the heat and there’s not anywhere air conditioned or naturally cool to go, the best thing to do is wear loose fitting clothing - shorts and t-shirts, preferably of the newer synthetic dry-fit material, and embrace sweating. That’s how your body cools itself. Just drink plenty of water!
Fans are nice- even in high humidity environments, the motion moves enough air past to make convection effective. Staying in the shade is pretty self-evident, but important as well.
At any rate, that’s what I’ve found from a lifetime in Texas- Houston and Dallas mainly, with playing high school football in August/September, and a couple of summers in college partially spent out on a surveying crew in June, July and August.
That’s not 95F ambient temperature, it’s 95F wet bulb temperature. Wet bulb is a function of heat and humidity. It’s measured like it sounds, a thermometer covered in a bulb of wet fabric in order to factor in the effects of evaporative cooling (or lack thereof).
Fans are always somewhat effective when the humidity is less than 100%. But when wet-bulb is over 95F, evaporative cooling is too slow to prevent most humans from overheating.
I was under the impression that the fan upper temperature was different than the wet bulb temperature, and didn’t really factor in humidity. It more has to do with ambient air temperature and body temperature.
Having said that, I did find this more up to date study that refutes the original 95F claim.
“Our study shows that if you are young and resting at home, then a fan has protective benefits up to 107.6 degrees and 50 percent humidity,” said Ollie Jay, a researcher at the University of Sydney, Australia, who led the study.
The study is published as a letter in the Feb. 17 issue of the Journal of the American Medical Association.
The current guidelines by public health officials vary, with some recommending upper limits for fan use that range from 90 degrees at 35 percent humidity to others advising no fan use above 96 to 99 degrees with no humidity level stated, according to background information in the study.
The investigators found that the fans prevented heat-related elevations in heart rate and core temperature up to about 80 percent relative humidity at 97 degrees and at nearly 50 percent humidity at 108 degrees.
However, Jay said he is not certain if the findings would apply to older adults. They would need to be studied before any conclusions could be made, he said.
What is behind the guidance not to use fans in extreme heat? Jay said he is not certain, but the guidelines may be based on the idea that “when air temperature goes above skin temperature, about 95 degrees, extra air flow will add heat to the body via convection.”