Bone-chilling temperatures have set in, the sort that trigger hallucinations of Hawaiian beaches. Temperatures have dropped to single digits at night and as low as -5°F in recent days.
That's without the windchill factor.
"Once the temperature drops below 20°F, but especially below 10°F, people really need to take more precautions," says Ron Walls, chair of emergency medicine at Brigham and Women's Hospital.
Any skin that's exposed on your face, hands, or rest of your body could become frostbitten in a short span of time, especially if it's windy -- which Boston usually is.
In 5°F temperatures and 30 mile-per-hour winds, for example, bare skin becomes frostbitten after being exposed for 30 minutes, according to the National Weather Service. (Check out their wind chill chart.)
Frostbite occurs when blood vessels near the skin constrict in the cold, sending blood rushing towards the trunk of the body to warm vital organs. But this leaves the skin exposed to the cold and more likely to become damaged. What's worse, you might be unaware of the injury taking place since nerves near the skin don't function well after the blood drains away.
"At first your skin feels painful, but then it feels numb," Walls explains. That's a sign to head indoors tout de suite. Quickly bathe the affected area in warm water, but get someone to test the temperature for you since your skin may be too numb to detect water that's hot enough to burn.
"Areas of skin that have been frostbitten before will more easily be injured by the cold again," says Walls. He recalls a female patient he once saw who became frostbitten on the back of her knees after walking her dog on a sub-zero day while wearing a short skirt, hose, and boots. "Every time she goes out on very cold days, that previously frostbitten area begins to hurt."
No question, it's best to avoid frostbite in the first place by remaining indoors as much as possible on ridiculously cold days or covering every square-inch of skin if you must be outside for an hour or two. Think like a skier: mask, goggles, snow pants, hat and ski gloves.
And protect your pets too. Keep them indoors and take your dog for a five-minute walk to do his or her business, recommends Walls, instead of a 20-minute one. While a dog's fur usually provides ample protection, its feet are prone to cold injury, so owners might want to consider investing in a set of doggie boots.
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