Though it sounds counterintuitive, hot tea may help on a hot dry day by making you sweat more. Certain nerve receptors in the mouth are activated by heat, which can trigger the brain’s thermoregulatory center to induce sweating. Evaporation of sweat cools the skin and helps lower body temperature. (In highly humid environments, however, sweat doesn’t evaporate as well from the skin, in which case a cold beverage is a better option.) Eating hot/spicy foods, like chili and ginger, activates the same nerve receptors.
Along with carbon dioxide, heat, and movement, mosquitoes are attracted to hundreds of chemicals that we secrete. Everyone produces the same chemicals, but in different proportions, which is what may make a person more, or less, appealing. Plus, different mosquito species are attracted to different chemicals. Some compounds may even conceal us from mosquitoes, and people who produce more of them are naturally better shielded.
For everyday activities, 10 to 30 percent DEET concentration is adequate. Oil of lemon eucalyptus is as effective as low concentrations of DEET; other botanical products provide very limited protection. Another option is picaridin, a synthetic compound that’s similar to piperine, a compound in black pepper. Use permethrin only on clothing (or wear permethrin-treated clothes); applying it to skin deactivates it. There’s no evidence that B vitamins or garlic help.
While citronella candles may repel some mosquitoes, you’d have to sit with your entire body in the smoky plume (not recommended). On the other hand, because mosquitoes are relatively weak and slow flyers, a simple fan (preferably oscillating) will keep them away. A fan also disperses the carbon dioxide you exhale, as well as body heat and odors that attract mosquitoes. Yellow lights attract fewer mosquitoes than white lights. Emptying water that collects in roof gutters, tarps, and gardening equipment eliminates mosquito breeding grounds.
That’s a myth. The rubber surfacing used in some outdoor tracks and playgrounds is not protective, either. If you are in an open area during a lightning storm, seek the lowest spot and crouch with your head down, feet together, making as little contact with the ground as possible—especially if your hair stands on end, a sign of an imminent lightning strike. Do not seek shelter under a tree. Sitting in a car with the windows rolled up is safer than being outside (don’t touch any metal parts), but a shed or lean-to is not.
The rash, caused by urushiol in the plant’s sap, can’t be transmitted from person to person; by the time the rash appears, the urushiol is gone. Pets don’t react to urushiol, but they can carry it on their fur and spread it to people. All parts of the plant, not just the leaves, can cause rashes—even if the plant is dead. Urushiol can survive on gardening tools as well as clothes and shoes for months, even years. Wear gloves and other protective clothing when engaging in activities where the plant might be; wash clothes afterward in strong detergent, and wipe off shoes before entering your home.
The newly regulated term “broad-spectrum” ensures that the sunscreen protects against both ultraviolet-A rays (UVA, responsible for skin aging) and ultraviolet-B rays (UVB, most responsible for sunburns and tanning; both promote skin cancer). Broad-spectrum sunscreens with SPF (sun protection factor) of 15 or higher may state that they decrease the risk of skin cancer and early aging when used with other sun-protective measures (such as wearing a hat and protective clothing). Use a broad-spectrum sunscreen with an SPF of at least 15—or at least 30 if you are very sensitive to the sun or have a personal or family history of skin cancer.
It depends on the product. Chemical sunscreens (such as avobenzone and octisalate), which absorb UV rays, take some time to be absorbed into the skin. Physical sunscreens (titanium dioxide and zinc oxide) block UV rays and are effective right away. Check the ingredients of the product; some contain both types. Reapply sunscreen at least every two hours, or more often if you swim (or sweat) a lot. Even water-resistant sunscreens need to be reapplied often—after 40 or 80 minutes of swimming (or sweating), as indicated on the label.
Umbrellas block direct UV rays from the sun—but not all diffuse radiation, which can also harm skin and eyes. A 2011 Spanish study found that as much as one-third of UV still reached the base of an umbrella that was three feet wide and almost five feet tall. Keep in mind also that beach umbrellas vary in how much direct UV they block. Some come with a UPF (ultraviolet protection factor) rating; a UPF of 50+ filters out 98 percent of UV.
But you can get other kinds of UV damage. Clear glass screens out nearly all UVB (most responsible for sunburn), but only windshields are treated to block UVA. People who drive a lot have a higher risk of developing skin cancer on the left side. If you are in a car for long hours on sunny days, wear long sleeves and/or use a broad-spectrum sunscreen, especially if you burn easily. You can also have the side and rear windows treated to block nearly all UV rays.
Swimming can improve cardiovascular fitness, as long as you swim at a brisk pace. Working out in water also reduces stress on the spine, promotes muscle relaxation, relieves joint stiffness and pain, and increases flexibility. Because swimming is not a weight-bearing activity, however, it doesn’t strengthen bones much. And though swimming burns a lot of calories, it usually results in less weight loss than other aerobic activities, like running. That’s because regular exposure to cold water may stimulate appetite to keep the body warm and may also encourage the body to maintain fat stores under the skin for insulation.
When uric acid (a component of urine) mixes with chlorine (a disinfectant), other substances are formed, including cyanogen chloride and trichloramine, which can affect the lungs, heart, and central nervous system. People with asthma may be particularly vulnerable to these substances. Though uric acid from sweat similarly reacts with chlorine, a new study in Environmental Science & Technology estimated that 90 percent of the uric acid in pools comes from urine. Swimmers should shower and use the toilet before swimming.
In fact, unless darker lenses are chemically treated to block UV, they can be more harmful than wearing no sunglasses, because they can cause pupils to dilate, allowing more UV to enter your eyes. Darker lenses do, however, block more visible light and minimize glare. Mirrored lenses can be helpful in very bright conditions, but you must make sure they are UV-treated as well. Look for a UV400 or “99-100% UV absorbent” label on sunglasses (though such labels are not independently verified); an optician can also test the UV protection of your sunglasses or can coat them, if necessary.
Stinging insects, particularly yellow jackets (a type of wasp), can be a real nuisance. It helps to avoid bright colors and prints, as well as perfume and other scented skin products. Sweet wet foods like watermelon, ice cream, and open cans of soda are also magnets for stinging insects. Contrary to popular belief, however, honey bees are much less of a problem—as one source said, “honey bees are too busy gathering nectar to spend time stealing food from some old human.”
Grilling produces heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). Several studies have shown that marinades can significantly reduce these carcinogenic compounds. For instance, a study in the Journal of Agricultural and Food Chemistry found that marinating pork in black beer for four hours before grilling reduced PAH formation by more than 50 percent. Other effective marinade ingredients include vegetable oil, citrus juice, vinegar, mustard, and herbs and spices. Sugars tend to increase these compounds, so limit how much you use in your marinade, or look for low-sugar commercial products.
Contrary to what your mother may have told you, swallowing the seeds won’t cause a watermelon to grow in your stomach. Both the small white (immature) seeds and the large black (mature) seeds are edible and nutritious. One ounce of dried black seeds has 160 calories (much from healthful unsaturated fats) and 8 grams of protein, plus manganese, zinc, magnesium, iron, and other nutrients. Want to try them? After rinsing and drying the seeds, coat them with olive oil and, if desired, a little sea salt or other seasonings; then spread them on a baking sheet and roast in a 325°F oven for about 15 minutes.
There’s conflicting information about what works best—it depends in part on the jellyfish species. Still, rinsing the area with seawater is often recommended; fresh water and alcohol may actually activate stingers. Urine is useless and may even make things worse. As for vinegar, another popular remedy, it may only help for some (not most) jellyfish species. According to a review by UC San Diego researchers, hot water immersion and lidocaine cream work best for stings from North American jellyfish. Get medical help for venomous stings, as from a Portuguese man-of-war or box jellyfish, or if you have pain for more than an hour or symptoms such as difficulty breathing.
One bout of this tick-transmitted disease does not make you immune, so always take precautions when you venture into tick-infested areas. Wear light-colored, long-sleeved shirts, socks, and pants; tuck pants into your socks. Use repellent on exposed skin; spray permethrin on clothing (see answer #3). When you get home, check for ticks all over your body, including your scalp and groin area. They can be hard to spot early on; a magnifying glass may help.
Use fine-tipped tweezers to grip the tick as close to your skin as possible and gently pull it straight away from you with a steady motion until it releases its hold. Twisting the tick may break off the mouthparts and lead to infection. Clean your hands and the bite area afterward with soap and water, rubbing alcohol, or an iodine scrub.
Using antiperspirant at night when you perspire less allows more of the active ingredient to be absorbed into sweat glands and plug up the pores. For even more protection, try a “clinical strength” antiperspirant, such as Secret Clinical Strength or Degree Clinical Protection, and apply it at bedtime.