It's summer in Minnesota: That means it's been hot and it — at some point — will get hotter still. Aside from hiding out in the multiplex all day watching "Elvis," most of us have developed a few strategies for staying cool. But does drinking hot coffee, wearing seersucker or firing up the swamp cooler really work?
We separate the myths from the facts about feeling cool.
Drink, eat and be cool
Q: Does drinking a hot beverage like coffee cool you down?
Here's why: Canadian researchers found that drinking hot water triggers the body to sweat more, which can have a cooling effect on the skin. You might get the same effect from eating spicy food. But this only works when it's not too humid and you're already drenched in sweat.
Q: What if it's both hot and humid? Is ice water best?
A: A slushy is even better.
Here's why: Because they're made with water and sugar, slushies act as a sort of antifreeze, slurpable at a lower temperature without freezing solid. There are currently sports medicine experiments testing "ice slurry" consumption as an alternative to ice baths to cool off hot athletes. Sports science journalist Alex Hutchinson said the Australian Olympic team hauled slushy machines to the 2008 Olympic games in Beijing hoping to get an edge at hot weather events.
Q: What if I don't have a slushy machine?
A: Try a breath mint.
Here's why: The sensation of menthol found in mint seems to make you feel cooler. One study showed that athletes who swilled a menthol solution while cycling in 93-degree heat were able to cycle longer than when they swilled an orange-flavored placebo solution. Another study found wearing a T-shirt soaked in a menthol solution helped runners improve their times running in the heat and humidity almost as much as putting on a T-shirt soaked in cold water.
Body and mind
Q: Can holding an ice cube to your wrist cool you down?
A: Not really. Try holding an ice cube or running cold water over the palm of your hand, instead.
Here's why: Certain areas of our bodies, like our palms, have specialized blood vessels that act as natural radiators, dissipating heat into the environment. Stanford University researchers designed a glove that runs cool water to the palm of the wearer's hand, cooling the body so effectively that it may help athletes recover from exertion faster and improve strength and endurance.
Q: Is there a psychological element to feeling hot?
Here's why: You can actually talk yourself into tolerating the heat better, at least if you're a trained athlete. Canadian researchers took some cyclists and had them pedal to exhaustion in 95-degree heat. Then the researcher divided cyclists into two groups, with one group given training in "motivational self-talk," saying things like "I am focused," and "Keep pushing" instead of "This heat is killing me." The motivational self-talkers were able to exercise longer and did better on cognitive tests.
Q: Does light-colored clothing keep us cooler than dark-colored clothing?
Here's why: Dark-colored clothing absorbs more solar radiation than light-colored clothing, which will reflect most of the visible wavelengths of light. But the cut of the clothing may also be important. A 1980 study of why Bedouins in the Sinai desert wear black robes suggested that loose fitting robes — even black ones — cooled the wearer through convection.
Q: Are breathable fabrics really cooler?
Here's why: Sweat is the main way our bodies keep cool, so thin, breathable fabrics like cotton and linen that allows air to circulate over our skin and evaporate sweat are ideal. Linen may have the edge because it wicks moisture away and it has a high "thermal conductivity," which means it feels cooler to the touch. Seersucker fabric has gaps that allow air to circulate. If you don't mind looking like Atticus Finch or Matlock, you'll feel cooler.
Q: What's the right way to use a ceiling fan?
A: There isn't one.
Here's why: "We try not to stress too much about which way your ceiling fan runs," said Jason Stevens, owner of Fan Man Lighting in Apple Valley. "The general idea is to [have the fan] blow down in summer so you feel the draft and up in winter so you don't. But it's really a matter of personal comfort."
Q: Do fans really lower the temperature in a room?
A: No, but they do make you feel cooler.
Here's why: The air from a fan creates a draft that causes the moisture on your skin to evaporate more quickly, explained Stevens. (It's called the windchill effect, but no Minnesotan would refer to it that way.)
Q: Do homemade air conditioners (aka swamp coolers) really work?
Here's why: Having a fan blow over a block of ice or bowl of ice cubes "does kind of cool the air temperature," said Stevens. But you have to be pretty close to feel the effect.
On the road
Q: Is it better for your gas mileage to turn on the A/C rather than open the windows?
Here's why: The make, model and engine size of your car have an impact, as does the car's age, the vehicle's speed and the weather. But in general, opening your windows at highway speeds causes drag that decreases your mileage, according to AAA. Likewise, running the air conditioner when the car is moving at slow speeds causes the engine to work harder, which decreases your mileage, according to the U.S. Department of Energy. So where's the cutoff point? Usually somewhere between 35 and 45 miles per hour.
Q: When you turn on the A/C in your car, is it best to turn it all the way up?
Here's why: If your car has been baking in the sun, do not put the A/C on max. In many cars, that setting increases the fan speed, which recirculates the hot air inside the car. The standard setting draws in cooler air from outside, which means the A/C has less work to do to get the air down to a comfortable temperature. Wait until the air in the car is cooled some before you crank the A/C.