This chart shows how long you can stay outside in extreme cold before getting frostbite
Simple temperature isn't the only thing that matters though. Brave adventurers (or those forced to leave their homes) should consider wind chill - the temperature it "feels like" outside based on the rate of heat loss from exposed skin, according to the National Weather Service.
Fingers, toes, ear lobes, or the tip of the nose are the areas most susceptible to frostbite. Your body works hard to keep internal organs and your head warm, and sometimes extremities get left behind.
Usually, when parts of your body get too cold, they turn red and hurt. Symptoms of frostbite, however, include a loss of feeling and lack of color. Anyone showing signs of hypothermia or frost bite should seek medical attention immediately.
The chart below shows how long you can be exposed to certain temperatures before resulting in frostbite.
For example, a temperature of 0 degrees Fahrenheit and a wind speed of 15 mph creates a wind chill temperature of -19 degrees Fahrenheit. Under these conditions frost bite can occur in just 30 minutes. With windchill, some areas on the Northeast could reach temperatures as low as -35 degrees Fahrenheit, according to the National Weather Service, which has issued "wind chill watches" for certain locations. At that temperature, frostbite can occur in as little as 10 minutes.
You can, however, survive a winter scenario like this. Check out these tips - like wearing mittens instead of gloves.
Extremely cold temperature can also cause hypothermia, when the body's temperature dips below 95 degrees Fahrenheit. Warning signs include uncontrollable shivering, memory loss, disorientation, incoherence, slurred speech, drowsiness, and obvious exhaustion, according to the NWS.
Surprisingly, hypothermia can occur at any temperature lower than normal body temperature. Factors like body fat, age, alcohol consumption, and especially wetness can affect how long hypothermia takes to strike.
If you fall into water, the situation becomes drastically more dangerous.
For example, in water 32.5 degrees Fahrenheit or colder, you might not survive more than 15-to-45 minutes. You'll undergo shock within the first two minutes and some functional disability before 30 minutes, according to the United States Coast Guard.
Check out this chart from the Personal Floatation Device Manufacturers Association: