Experts Warn Fans May Harm More Than Help During Extreme Heat Waves

During extreme heat waves, the use of fans can sometimes cause more harm than benefit, experts warn. While air conditioners rapidly lower room temperatures and maintain a stable, cooler environment, they consume significantly more electricity and require regular maintenance. Overuse or setting air conditioners to very low temperatures can dry out the air, leading to dry skin, irritated eyes, and respiratory issues, especially for allergy or asthma sufferers. Additionally, because the body does not sweat as much in air-conditioned environments, dehydration can occur unnoticed.

Fans, including ceiling fans, do not lower room temperature but circulate air to help sweat evaporate faster, which is effective in moderate heat. However, in extreme heat conditions where the ambient temperature exceeds body temperature, fans can worsen heat exposure and dehydration by blowing hot air continuously over the body. The U.S. Centers for Disease Control and Prevention (CDC) notes that fans may not prevent heat-related illnesses in very high temperatures and can sometimes exacerbate dehydration.

To improve fan effectiveness without overburdening the body, experts recommend using external breezes and shading rooms to reduce heat. Sudden temperature changes, such as moving from an air-conditioned room to intense outdoor heat, can also stress the body, causing headaches or fatigue. Ultimately, choosing between air conditioning and fans depends on various factors, including temperature severity and individual health conditions.