While weather can be exciting or a nuisance (depending on which season you're fond of…), it can also be quite dangerous. In light of the brutal cold stretches we’ve had in the past several years in the eastern half of the U.S., it has become pertinent to talk about the dangers of hypothermia and frostbite. Hypothermia, in particular, kills up to 1,500 people in the US every year. While this is a frightening statistic, it's most certainly preventable. So, let’s first delve into some science!
Humans have a self-regulatory mechanism that keeps our bodies roughly between 97.7-99.5 degrees (contrary to popular belief, it doesn’t exactly have to sit near 98.6 degrees, as this is just an average). Hypothermia is defined when our body temperature dips below 95 degrees. So much like when we get fevers even just hitting 100 degrees, it does not take much to start causing problems when we become cold. The warmth from our bodies creates a thin layer of warm air near our skin, acting as an insulator in a way. However, this layer gets wicked away when it is windy, which is why stepping outside can feel like a mistake sometimes. However, this is exactly what wind chill is! It is not the real air temperature, but rather the apparent temperature we feel due to the wind. The longer cold air continuously hits exposed skin, the more likely it is that it can turn into a problem.
In any kind of cold weather, our bodies will try to restrict blood flow away from our core (to the limbs and appendages), which is why our hands, feet, nose, and ears quickly turn cold and red (although we all know that one person with consistently cold hands!). While this helps keep our internal organs warm, it also exposes us to frostbite if they are not properly covered. A wind chill near or below -20 degrees will result in frostbite within 30 minutes or less. For instance, a 5-degree day with 30 mph winds will send the wind chill this far down. In fact, the National Weather Service maintains a graph (shown below) of temperature versus wind speed, and how quickly frostbite can occur. Signs of frostbite include pale or white looking skin. Even worse, when feeling becomes lost, this indicates that skin tissue is being damaged. 
While hypothermia does not necessarily coincide with frostbite, being exposed to cold temperatures for extended periods of time will eventually catch up to you. At some point, your body just cannot keep warm where it normally should be because there is too much heat loss occurring. And believe it or not, this can occur even when it is as “warm” as 50 degrees outside. This is why we are told time immemorial to try and keep dry and to dress in layers.
Unfortunately, some do succumb to the effects of it. The warning signs do become rather noticeable, with excessive shivering, drowsiness, slurred speech, and memory loss among them. Many will enter only a mild case of this, in which case requires additional warmth, warm fluids, and moving indoors. However, if not attended to in a timely manner, this can easily slip into severe cases of hypothermia, which requires immediate medical assistance as death can occur.
Fortunately, the Northeast does not always give us such cold periods for an extended amount of time, especially in mild winters. However, frostbite and hypothermia are serious concerns when it is well below freezing outside. Dressing in layers helps trapped air work as an insulator, and keeping hands and your head covered is a must. Whether it is raining or snowing, keeping dry is extremely important as well, as it only speeds up the process of frostbite and hypothermia; evaporating water will cool exposed skin further (which is great in summer but not winter)!
In the end, it is best to just stay indoors as much as possible when temperatures take a nosedive. If you happen to work outside, dress in layers and take time to go inside once in a while to warm up your body. Always take precautions and stay safe!
