Home / 25 Frequently Asked Questions About Cold Snaps and Their Answers

When we think of natural disasters, we usually think of serious, breaking-news crisis-level events like hurricanes, tsunamis, earthquakes, tornadoes, etc. But these are not the only natural disasters that pose a serious risk to people living in the United States and across the world. Other disasters can occur in the form of more sinister, less obvious natural events, like a sudden and serious change in temperature.

A cold wave can be caused by various factors, from atmospheric conditions to ocean currents. To take a recent incidence from January 2020, the air in the atmosphere above the Arctic warmed suddenly. It caused a weakening of the polar vortex (the collection of winds that keep cold air at the North Pole). This weakening allowed cold winds to spill into regions of Asia, North America, and Europe. The deep freeze that spread across the southern U.S. put 157 million Americans under severe winter storm warnings, and it shut down much of the power grid in Texas.

The following states are most at risk for deep freezes, cold snaps, and other serious winter weather events. Bear in mind though, such events can technically occur anywhere in the United States. The following states are just where they occur most often:

  • Alaska
  • North Dakota
  • Maine
  • Minnesota
  • Wyoming
  • Montana
  • Vermont
  • Wisconsin
  • New Hampshire
  • Idaho
  • Michigan

It really depends on the specific weather event, where it occurs, and what time of year it occurs, but a cold spell can last anywhere from a few hours to several days. Several factors contribute to how long such a cold weather event lingers.

Different factors contribute to what temperatures constitute a cold snap or deep freeze. For example, wind chill, (the sensation of colder weather as a result of wind speeds moving over the ground during cold temperatures), can greatly influence a cold snap. But generally speaking, the temperatures range between 28F and -20F during cold snaps.


Such events put humans at risk for experiencing hypothermia, a life-threatening emergency medical condition. Such events cause serious harm. When the temperatures drop low enough, machines stop working, including personal automobiles, snowplows, airplanes, trains, and even power plants. Deep freezes can also seriously disrupt agriculture.

The primary difference with these freezing weather events is their extreme and unusual characteristics. A cold wave denotes a temperature drop that is extreme and unusual for that geographic area, hence the abundant risk factors.

While it would seem that a warming planet would lead to fewer deep freezes and cold snaps, the opposite may be true. Some scientists suggest that melting polar ice caps and a warming Arctic and Antarctic regions will drastically change jet streams. The result? Severe weather like cold snaps, deep freezes, frosts, etc.

Deep freezes are not discussed as often as other natural disasters. And that's mainly because they are not as newsworthy or eye-opening as hurricanes, tornadoes, earthquakes, or tsunamis. But they are no less dangerous. Deep freezes, also called cold waves, cold snaps, cold spells, and cold wave disasters can be extremely harmful if one does not prepare for them.

Also called a "hard freeze," a deep freeze is delineated by the National Weather Service as, “A hard freeze is possible when temperatures fall below 28°F.” Simply stated, cold snaps, cold waves, and cold spells all refer to the same event as a deep freeze, i.e., a serious and life-threatening drop in temperature.

It certainly can. According to the National Weather Service, “Exposure to cold can cause frostbite or hypothermia and become life-threatening. Infants and elderly people are most susceptible. What constitutes extreme cold varies in different parts of the country. In the southern U. S., near freezing temperatures are considered extreme cold. Freezing temperatures can cause severe damage to citrus fruit crops and other vegetation. Pipes may freeze and burst in homes that are poorly insulated or without heat. In the north, extreme cold means temperatures well below zero.”

Here are some tips to follow if you find yourself caught in a serious cold air outbreak:

  • For a deep freeze, wear layers on top of layers on top of layers! The more warm clothes, the better.
  • Get indoors if possible. Even if the power is out, the building's walls will provide some shelter.
  • Cover as much bare, exposed skin as possible to prevent frostbite.
  • If sheltering in place with multiple people, huddle together to conserve body heat.
  • If stuck outside during a deep freeze, keep moving, and do your best to seek shelter.

The key factor during a cold weather event is the sheer importance of staying warm. Fuel, warm clothes, layers, blankets, the ability to make a fire, food and water for sustenance and caloric burn, heaters, battery-powered devices, generators, all of these items should be kept on-hand as they could be life-saving during a cold wave.

This depends entirely on how much clothing the person is wearing and just how cold the cold snap is. In below-zero Fahrenheit weather, a human who is not properly clothed may only last a few minutes before they get frostbite, and perhaps just a few minutes longer before they start to experience hypothermia. According to one resource, "At minus 30F an otherwise healthy person who isn't properly dressed for the cold could experience hypothermia in as little as 10 minutes. At minus 40 to minus 50F, hypothermia can set in in just 5 to 7 minutes.” Once someone succumbs to hypothermia, they may only have a few minutes before their heart stops.

While these conditions are very similar, there are distinct differences. Quoting a medical authority, “Frostbite is an injury caused by freezing of the skin and underlying tissues. First your skin becomes very cold and red, then numb, hard, and pale. Frostbite is most common on the fingers, toes, nose, ears, cheeks and chin. Exposed skin in cold, windy weather is most vulnerable to frostbite. But frostbite can occur on skin covered by gloves or other clothing. Frostnip is a milder form of cold injury that doesn’t cause permanent skin damage. You can treat frostnip with first-aid measures, including rewarming the affected skin. All other frostbite requires medical attention because it can damage skin, tissues, muscle and bones. Possible complications of severe frostbite include infection and nerve damage.”

The key to preventing either of these conditions is to ensure that as much skin as possible is covered when going out in very cold weather. While layers are immensely important in surviving cold outdoor temperatures, ensuring all skin is covered is especially critical. Pay particular attention to covering the hands, feet, head, face, and neck.

The first step to treating such conditions involves moving out of the cold environment and into a warmer environment, then removing wet clothing if such is present, then slowly and gradually rewarming the affected area. From the May Clinic, “Check for hypothermia. Get emergency medical help if you suspect hypothermia. Signs of hypothermia include intense shivering, drowsiness, confusion, fumbling hands and slurred speech. Protect your skin from further damage. If there's any chance the affected areas will freeze again, don't thaw them. If they're already thawed, wrap them up so that they don't refreeze. If you're outside, warm frostbitten hands by tucking them into your armpits. Don't rub the affected skin with snow or anything else. And don't walk on frostbitten feet or toes if possible. Get out of the cold. Once you're in a warm space, remove wet clothes and wrap up in a warm blanket. Gently rewarm frostbitten areas. Don't rewarm frostbitten skin with direct heat, such as a stove, heat lamp, fireplace or heating pad. This can cause burns. Drink warm liquids. Tea, coffee, hot chocolate or soup can help warm you from the inside. Don't drink alcohol.”

If you live in an area that is prone to experiencing cold air outbreaks, consider investing in a backup source of power, such as a generator, solar panels, or a wind turbine.

You can eat any food during a cold wave, but warmth-inducing foods like soups, casseroles, oven-baked foods, hot teas, coffees, and cocoas help keep the body warm.

If the car is not operable and you cannot start the car and run the heater, the car will not serve as a significant source of protection for you, as cars are not as well-insulated as most homes are. However, a car does offer more protection from the elements than being fully exposed.

Most people cannot survive if their core body temperature drops below 75 degrees Fahrenheit, which can occur in temperatures below freezing. While such is less likely to occur while in a car (as your own body heat will help to heat the interior of the car) if the outside temperature is extremely cold (single digits or below zero), the car will not save you.

Here’s a quick list of supplies you should have on hand during a severe cold weather event:

  • Water
  • Blankets
  • Flashlights and flares
  • Shovel
  • Tools and supplies
  • First aid kit
  • Warm, waterproof gear
  • Maps and a compass
  • Bivouac sack or space blanket
  • Portable power source
  • Fire-starting tools
  • Multi-tool
  • Non-perishable food
  • Winter car supplies

The main focus has to be on conserving body heat. The two rules of thumb for staying warm and conserving body heat during a severe cold weather event involve wearing plenty of layers and covering as much skin as possible.

Cold wave disasters are caused by the same weather effects as those that cause cold snaps (see below). The only difference is that cold waves are more widespread, they last longer, and they cause more damage. According to one resource, “The damage arising from cold waves is mainly caused by the accompanying effects. Heavy snowfall can give rise to traffic chaos. Fatal accidents can occur if people fail to adapt their driving to road conditions. Ice rain can cause ice fractures in trees and telephone wires. The homeless, people who must spend time outdoors (e.g. for work) and the elderly are particularly vulnerable to the effects of cold waves.”

The science on this is pretty straightforward. Such events are caused by a cooling of the air. According to one body of research, “A cold wave develops when cold air masses over large areas are brought in. This occurs mainly during winter months when cold air masses are transported from the polar region. In those northern areas cold air develops to a large reservoir due to low or even missing solar radiation during short autumn and winter days. Particular weather conditions can transport these air masses as far as Central Europe. The fall of temperature is of the order of 10°C within a few hours. Cold air masses are only slowly moving, therefore, a cold wave will normally last for several days.”

One of the best ways to protect oneself and others from a cold spell is to closely monitor weather reports when conditions indicate excessive heat or cold. There is usually sufficient warning of a cold spell, as predictive weather conditions often manifest themselves clearly in the days leading up to the event. Keeping an eye on the weather channel is a good way to help prepare for a heat wave or a deep freeze.

Here is a term to watch out for:

A frost advisory indicates that the temperature may fall below 32 degrees Fahrenheit, whereas a frost warning suggests it is almost certain that the temperature will fall below 32 degrees Fahrenheit. This would be the time to bring the animals and children inside, make sure you have enough food, water, and fuel, and bring out the warm blankets and layered clothing.

The first priority must be to get out of the cold weather as soon as possible. In addition to that, surviving deep freeze disasters comes down to wearing multiple layers, covering as much of the body as possible, and staying out of the wind.

In most years, between 70 and 100 Americans die from deep freeze weather events. But in particularly extreme cases, dozens of people can die in just one deep freeze (witness Texas's deep freeze event in January 2020, in which over 100 residents froze to death).

The worst deep freeze in modern U.S. history was a combination of a deep freeze and a winter storm. It was the Great Blizzard of 1993 when 40% of the U.S. population was affected by blizzards in 26 states. Millions lost power, all major airports on the East Coast closed down, and four feet of snow blanketed much of the U.S. The storm cost about $8 billion, and 270 people died due to the cold and the storm.

Not surprisingly, animals do tend to be better adjusted to surviving cold temperatures than humans. While a human being would have a hard time sleeping outside in 30 degree Fahrenheit weather conditions, most livestock can withstand this temperature just fine. But below zero Fahrenheit temps are quite dangerous for most animals too.