I have heard that fans are no good at high temperatures. How so?
—Bob Foster, Midlothian
Fans provide wonderful cooling most of the time, but air movement created by a fan when temperatures climb above 95 degrees encourages the flow of heat into the human body. Then, the use of fans proves ineffective. At cooler temperatures, fans provide air movement that helps transfer heat from our bodies into the air. The evaporation of perspiration, which occurs more efficiently when air is moving, provides an even more powerful means of removing heat from our bodies. At readings of 95 degrees or higher, fans may cause the body to gain heat instead of lose it, effectively raising body temperature. When temperatures rise, staying hydrated is critical.