Can heat-related illness strike even when it’s not extremely hot?
Even when temperatures are not extremely high, humidity, sun exposure, exercise, and inadequate water intake can each help trigger and increase the risk of heat exhaustion. For example, if the humidity is 90 percent and you’re in direct sunlight, 35 degrees could feel like nearly 39 degrees. Exercising or drinking too little water can turn up the heat even further.
People who aren’t used to the heat are particularly vulnerable to heat illness. Others at risk include young children and people over age 65 or so; those who are overweight, out of shape, or dehydrated; people with neurologic or heart disease; and those taking certain medications that affect the body’s ability to cope (see table above on "Drugs that intensify sun and heat").
To stay safe: Acclimatize to warmer temperature gradually before your summer outdoor activity by getting out for at least 30 minutes a day for two weeks or more. When it’s very hot or humid, limit your activities, seek shade, drink plenty of fluids, and consider staying indoors. Mild heat-related symptoms, such as fatigue, swelling of the hands and feet, prickly heat (an irritating rash caused by blocked sweat pores) are signs that you need to cool off to avoid serious trouble. Seek immediate help if you develop any of these symptoms of heat exhaustion or heat stroke during and after hot or humid weather: confusion, lethargy or agitation; intense muscle aches, fever, or nausea; convulsions or even a fleeting loss of consciousness.
Do darker sunglasses protect your eyes better?
The darkness of the glasses has nothing to do with their protectiveness against the main types of ultraviolet radiation, UVA and UVB. Instead, a chemical in or on the lenses does the job.
To stay safe: Choose sunglasses labeled as meeting American National Standards Institute (ANSI) requirements for general purpose use, which block at least 95 percent of UVB and 60 percent of UVA radiation. While that’s not enough for most people, sunglasses labeled as absorbing 99 or 100 percent of UVA and UVB may be best for those who have cataracts or take drugs that increase the risk of sun-induced skin and eye damage. Use sunglasses even if you wear contact lenses with UV protection, which don’t cover the entire eye.
Are insect repellents that contain deet too risky to use regularly on children?
Products containing deet are safe if used properly. Canadian researchers sifted through all reports of adverse reactions to deet over the past half century. Their review, published in the August 2003 Canadian Medical Association journal, found that serious side effects in adults were confined mostly to people who ingested the chemical. In children, they found a few reports linking skin use of deet to seizures. But all occurred before 1992, and none definitely ruled out other causes. The risk of catching a dangerous disease, such as dengue or malaria, from an infected mosquito is far more worrisome than the very slight risks from deet, which is still the best way to prevent those illnesses.
To stay safe: To minimize any possible risk from deet, choose a product with the lowest concentration that works for you. (Higher concentrations don’t work any better though they last slightly longer.) Use no more than the label directs. Don’t apply it near the nose and mouth or on broken skin, and don’t apply it beneath your clothes which increase skin absorption. When you come home, wash the repellent off. The American Academy of Pediatrics now says deet concentrations up to 30 percent are safe on children over two months of age. Young children shouldn’t apply the product themselves, and parents should keep it off the hands of their kids.
When using sunblock, do we also apply it under our clothing or just on the exposed part?
You can get sunburned right through fabrics that let pinpoints of light shine through when they’re held up to strong illumination, particularly if they’re light-colored. Clothes that are wet or tight also let in more sunlight because they tend to stretch. That is why it is a good idea to wear sunblock under your clothing at certain times.
Shade and clouds are also unreliable shields. For example, if half the sky is visible through a leafy tree canopy, the tree protects you only as much as a very weak sunscreen with a sun protective factor (SPF), or potency, of 2. Under a beach umbrella, you still get 40 to 50 percent of the sun’s radiation, since it reflects off the sand and sky. Even on overcast days, 10 to 50 percent of the sun’s radiation penetrates the clouds.
To stay safe: Consider boosting the sun-shielding abilities of your clothes by washing them with a laundry detergent that contains brighteners, which absorb ultraviolet radiation. But for prolonged or intense sun exposure, use sunscreen and don’t rely just on clothing or shade. To protect your clothes, let sunscreen soak into your skin for about half an hour before getting dressed.
If you’re stung by a bee, do you remove the stinger quickly any way you can?
The answer to that is yes. The old advice was to gently scrape out the stinger and attached venom sac with a fingernail, knife blade, or credit card to avoid squeezing the sac and injecting more venom. But a 1996 study showed that speed is the key factor. Sting victims were left with welts of about the same size regardless of how they removed the stinger, but welt size increased by 25 percent when removal time jumped from two to eight seconds.
To stay safe: Remove the stinger immediately with whatever’s handy  including your fingernails  and don’t waste time looking for a tool.
Is spoiled mayonnaise in picnic food most likely to cause food poisoning?
That notion stems from the days when people often made mayonnaise and salad dressings from scratch, with raw eggs, which can harbor salmonella bacteria. Commercially prepared products use pasteurized eggs. And the acidity of their vinegar, salt, and citric juice kill some types of bacteria. In fact, a review article published in the Journal of Food Protection in 2000 found no case of food-borne illness linked directly with commercial mayonnaise or salad dressing. Far more likely to make you sick: unwashed fruits and vegetables and undercooked meats.
To stay safe:
• Wash fruits and vegetables thoroughly, including those you peel.
• Keep your cooler as cool as possible by leaving it in the shade covered with a blanket or, at the beach, partially burying it in sand.
• Place perishables in watertight containers to avoid contamination from melting ice, and put leftovers back on ice as soon as possible.
• Wash your hands and all surfaces and cutting tools that the food will touch before preparing or eating it. If there’s no water, bring wet washrags or towelettes.
• Don’t let raw meats touch the same surfaces as other food. Brownness is a poor indicator of doneness, so bring a meat thermometer if you grill. Chicken legs and thigh should be cooked to 180 degrees; chicken breast, 170 degrees; hamburgers, 160 degrees; pork, 160 degrees; and steaks, 145 degrees.
Hope you’re enjoying a safe summer!