The thought of heading into another brutal heat wave this weekend may have you feeling like a heat-pummeled, melting face emoji unable to get off the couch. For me, that’s compounded by the fact that I don’t have air conditioning anywhere in the house but for a small, rickety wall unit in the bedroom — and only installed recently.
Instead, I use multiple electric fans to create a cross breeze, often sticking my sweaty, flushed face directly in front of the fan grill.
Do not do this.
According to the Centers for Disease Control and Prevention, using electric fans in a heat wave of 90 degrees or more can actually make you hotter and can be dangerous for your health. Why? The fan acts as a convection oven, an appliance that circulates hot air in order to cook food quickly and evenly. In your home, during a heat wave, electric fans do the same: blow extra hot air around, potentially raising your body temperature instead of cooling it down. And that puts you at an accelerated risk for dehydration and heat exhaustion.
“It’s definitely true that if you’re blowing air warmer than your skin over your body, then you’re warming your body,” says David Eisenman, professor of medicine and co-director of the UCLA Center for Healthy Climate Solutions. “That heat wave mistake can be harmful. You’re warming yourself up and it increases the temperature inside your organs, including the heart and the brain and the blood. That can lead to dehydration, heat illnesses, and it can lead to cellular breakdown that makes heart disease or any other chronic illnesses that people have worse.”
It’s important to note, however, that the CDC’s temperature threshold is conservative, Eisenman says. Normal body temperature is about 98.6 degrees. Your skin — the surface of your body — is closer to 95 degrees. “That’s why international bodies, like the World Health Organization, say 95 degrees is the limit at which you should no longer use fans,” he says. “A young healthy person can still use their fan if it’s less than 95 degrees.”
The CDC chose 90 degrees as its fan safety cutoff point because “it fits all age groups and all circumstances,” Eisenman says, adding that humidity, age and the temperature inside someone’s home — which can be hotter than outside — could all make the safety threshold for using fans lower than 95 degrees. “When you’re doing math messaging, you have to have one simple message for everyone,” he says. “The CDC got more conservative and said let’s drop it down a few degrees. I think we should stick with what the CDC says.”
This weekend is expected to see highs of 95 to 110 degrees in the valleys, with portions of the Antelope Valley potentially reaching 115 degrees, and 100 to 110 across the Inland Empire. So are those of us without AC just out of luck?
Not necessarily.
Eisenman and V. Kelly Turner, associate director of heat research at the UCLA Luskin Center for Innovation, shared strategic tips for keeping cool sans fans.
