12 myths of summer

Get the facts on staying healthy and comfortable when the temperature rises.
© MSN Healthy Living // © MSN Health

What’s the best way to cool off on a hot summer day? Can seawater sterilize a cut and butter ease the pain of sunburn?  Is poison ivy contagious? Experts chime in on the cool facts behind these and other popular summer myths.

-- By Linda Melone for MSN Healthy Living
1 of 14 Sunrise (Manuel Gutjahr/Getty Images)

The myth: Cold showers cool you off fastest

The cool facts: Jumping into a cold shower on a hot day sounds logical, but it may not cool you off as planned. “Suddenly going from hot to cold causes your body’s defense mechanism to kick in,” says Dr. Balu Gadhe, internal medicine specialist and senior medical officer with CareMore, a medical group in Cerritos, Calif. The body possesses a natural mechanism that preserves its core temperature. When you are hot and suddenly get into a cold shower, your blood vessels constrict, which stops you from “taking in” the coolness, Gadhe says. To avoid this self-protective reaction, Gadhe recommends showering with tepid water instead of cold. The best way to beat the heat: Eat or drink something cold, which lowers your body’s core temperature.

2 of 14 A cold shower (Joeyful/Getty Images)

The myth: You can't get sunburned on a cloudy day

The cool facts:  If you skip sunscreen on a cloudy day, you’re setting yourself up for a nasty sunburn. “The UV rays go through the clouds,” says Dr. Debra Jaliman, a New York-based dermatologist and author of "Skin Rules: Trade Secrets from a Top New York Dermatologist" (St. Martin's Press, 2012). “You need to wear sunscreen every day, even on a cloudy day. I have seen some of the worst sunburns on patients who failed to use sunscreen on cloudy days playing tennis or at the beach.” Jaliman recommends wearing a broad-spectrum SPF 30 every day. Look for products with zinc oxide or titanium dioxide. 

3 of 14 Woman walking on cloudy day (Juan R. Fabeiro/Getty Images)

The myth: Any drink can hydrate you

The cool facts: Not all summer drinks hydrate you the same way. “Certain beverages have a diuretic effect, which leads to dehydration,” says Amy Jamieson-Petonic, MEd., RD, CSSD, LD, a dietician with the Cleveland Clinic. Caffeinated beverages, drinks high in added sugars and alcoholic beverages can all lead to dehydration in different ways. Beverages high in added or refined sugars, such as sodas and fruit drinks, require that the body pull more fluid from the cells to metabolize and eliminate them. “Ironically, this leads to a vicious cycle of being thirsty from the beverage that you consumed to quench your thirst,” says Jamieson-Petonic. Water works best, then low-fat milk, 100 percent fruit juices, low-sodium vegetable juices and herbal teas. Sport drinks work well if you're exercising for longer than an hour. If you don't like the taste of water, try adding cucumber, strawberries, raspberries, lemon or lime.  

4 of 14 Woman drinking water (Sarah Fix Photography/Getty Images)

The myth: You burn more calories in warm weather

The cool facts: Working out in extremes of heat or cold requires your body to adjust, but the number of calories you burn isn’t enough to justify an extra scoop of ice cream.  “In extremes of cold or hot, your metabolism rises just to keep you at normal body temperature,” says Irv Rubenstein, PhD, exercise physiologist and founder of S.T.E.P.S., a fitness facility in Nashville, Tenn.  If you exercise in the heat, you raise your body temp to the point where you start using some calories to perspire, but your body can readily adjust, so it's inconsequential, Rubenstein says.

5 of 14 Woman running on a nice day (Jordan Siemens/Getty Images)

The myth: Longer days disrupt your sleep cycles

The cool facts: It may seem that you’re in bed when the sun has barely set, but the extended daylight won’t disturb your sleep cycle, says Dr. David Volpe, sleep expert and founder of Eos Sleep Centers in New York and California. “Our bodies are on a schedule and aim to get around eight hours of sleep per night; therefore, regardless of the daylight hours, as long as you continue your bedtime routine you won’t be disrupted.” If you find the longer daylight hours of summer leave you more awake later in the evening, unwind one hour before bed (turn off all technology and avoid vigorous exercise) and sleep in a cool, dark bedroom to help keep your sleep schedule consistent.

6 of 14 An owl in the moonlight (Ricardo Reitmeyer/Getty Images)

The myth: Air-conditioning increases risk of catching cold

The cool facts: Next to a dip in a pool, nothing beats an air-conditioned room to help cool off on a hot summer day. But some believe the drop in temperature may increase the risk of catching a cold. “Not so,” Gadhe says. “Colds are caused by viruses, not cold air.” Those with allergies may be at a higher risk of having an allergic reaction, however, if the air conditioning filter isn’t changed regularly. “Air conditioning also takes the humidity out of the air, which can cause sinuses to dry out, triggering allergic reactions in some people,” Gadhe says. Change your air conditioner’s filter regularly (recommendations vary, depending on the type of filter).

7 of 14 A woman in an air-conditioned room (Rachel Huson/Getty Images)

The myth: Seawater can heal a cut

The cool facts: Wading into the ocean when you have an open cut on your body is not a good idea, says Dr. Aileen M. Marty, professor in the department of molecular microbiology and infectious diseases at Herbert Wertheim College of Medicine in Miami. “Seawater is teeming with microorganisms of all kinds, including a number of very nasty bacteria. Dirty water, soil and sand can cause infection.” A sterile saline solution or bottled water is acceptable. If one of those is not available, seawater can work in a pinch, Marty says, “But get the wound cleaned up with clean water as soon as possible to avoid infection from contamination.”

8 of 14 A kid running in the ocean (Westbury/Getty Images)

The myth: Butter eases sunburn pain

The cool facts: When your skin feels on fire, butter sounds like a soothing solution. But don’t do it. “It's like putting oil on a fire,” says dermatologist Jaliman, “If you’re burned, it's best to use unscented aloe vera gel or even a topical hydrocortisone cream.” Cool compresses from skim milk half diluted with ice water and left on for 15 minutes at a time can also help. To ease the redness, Jaliman recommends taking aspirin for its anti-inflammatory effect.

9 of 14 A woman putting butter on a sunburn (Sara Lynn Paige/Getty Images)

The myth: Poison ivy is contagious

The cool facts: Poison ivy, oak and sumac rashes are triggered by an allergen called urushiol. You come in contact with urushiol by direct or indirect contact, through touching the leaves of a poisonous plant or through touching clothes, tools or pets that have the oil on them. However, it’s not contagious simply by coming in contact with a person who has it, says Dr. Adam Friedman, assistant professor of medicine and director of dermatologic research at Albert Einstein College of Medicine in the Bronx, N.Y. “The resin is so sticky it’s easy to spread. If it’s in your nail bed and you scratch another part of your body, you can spread it that way. Or if it’s on your pet’s fur you can also get it.” Remove all clothing after returning from a walk in the woods to avoid passing the resin on to your skin.

10 of 14 Poison ivy (Steve Ogle/Getty Images)