MARY LOUISE KELLY, HOST:
Have you ever noticed people using those odd-looking gadgets to fight the summer heat, like the little fans that sit around their necks and blow air? The idea is it helps cool you down, but does it work? NPR's Bill Chappell is on a mission to find out.
BILL CHAPPELL, BYLINE: On a late July morning, the sun is already broiling the National Mall in Washington, D.C. The air's so humid, even a loose shirt quickly turns into a sticky mess. I'm looking for people who are using those neck-cooling fans to get some relief.
CHRISTA SEGER: Oh, these are amazing.
CHAPPELL: Christa Seger is sitting with her kids in the shade near the Washington Monument. She holds up a fan. It looks like a thick plastic horseshoe that hangs around your neck and has dozens of vents that blow air toward your head.
SEGER: I can't believe how cold they get.
CHAPPELL: Seger is visiting from Denver where she bought two fans a few days ago. They cost about $25 and can run for four to six hours. Her daughter's been wearing one as they walk to museums and ice cream trucks.
SEGER: We have never used them before, and she loved it yesterday.
CHAPPELL: Some of these devices can cost hundreds of dollars, but I'm trying out a basic model today.
(SOUNDBITE OF FANS BLOWING)
CHAPPELL: Air starts whooshing past my ears and neck. It feels like a nice breeze. But is it really doing anything? I put that question to Chris Tyler, a researcher in environmental physiology at the University of Roehampton in London.
CHRIS TYLER: They're doing something. What they are doing is that they're making the wearer feel cooler.
CHAPPELL: The key word there is feel. Tyler says a small neck fan can make someone feel more comfortable without actually doing much to lower their body temperature. But because we have lots of thermal receptors in our neck and face, it can feel nice. But Tyler says...
TYLER: This is not a treatment. It's a bit like playing sport with a painkilling injection. The issue is still there. It's just that you can't detect it for a little bit.
CHAPPELL: Think of the main strategy our bodies use to cool down.
CECILIA KAUFMAN: The biggest thing is being able to evaporate the sweat off your body.
CHAPPELL: That's Cecilia Kaufman, director of occupational safety for the Korey Stringer Institute at the University of Connecticut.
KAUFMAN: The problem is when it's hot and humid, that sweat does not evaporate as quickly off your skin.
CHAPPELL: You might feel more comfortable using a neck fan, even if it's blowing humid air, but it only affects a small area of skin. Tyler says the most important thing is trying to cool as much of the body's surface area as possible.
TYLER: So the best way to cool down would be basically to take all your clothes off, expose the entire body to the air and let all of the sweat evaporate. But you'd get arrested, so that's a that's not a recommendation.
CHAPPELL: Back on the National Mall, we're all sweating through our clothes. The sun is blazing as I bump into Jeffrey Pagulong and his son Christof at the Lincoln Memorial. They're visiting from Boston, and both are wearing neck fans.
JEFFREY PAGULONG: It's kind of, like, 95 degrees right now, and wearing these fans kind of helps a lot. It cools down your head. So it helps.
CHAPPELL: You can probably hear the fan there in the background. So I ask, is the noise annoying?
J PAGULONG: Yeah, you can hear the fan, but it's fine. It's better to have it. I mean, the noise is much better than the heat, you know?
CHRISTOF PAGOLONG: Yeah.
CHAPPELL: As we speak, the heat index is maxing out at around 103 degrees. So yeah, right now, anything seems better than feeling the heat. Bill Chappell, NPR News.
(SOUNDBITE OF A.V. HAMILTON AND HIJNX SONG, "DOWN!") Transcript provided by NPR, Copyright NPR.
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