Extreme cold can be dangerous especially if you find yourself with a broken furnace.

 There are ways to stay warm if your heat goes out when it's very cold. One way is to use an alternative heat source. If your home has a gas, electric, or wood-burning fireplace, you have a built-in secondary heat source. Portable space heaters can also be used to warm up small spaces and rooms. They do require a lot of power to run, so be careful not to overload you electrical system by using too many. And never leave a space heater unattended because they can pose a fire hazard. Focus on warming one room of the house to minimize the heat that must be produced.

Block cold air by adding temporary insulation over doors and windows by haging blankets over them or closing the drapes tightly. A rolled up towel or blanket placed along the bottom of a drafty door or window will also help keep out the cold.

Wear extra layers of clothing and use blankets and sleeping bags for warmth. Drink warm liquids and eat hot soup to warm up from the inside. Moving around and staying active will also help. While sleeping, use heating pads and heated blankets to warm your sleeping area, though it is safest to turn these things off before you fall asleep. Hot water bottles are also a good alternative.

Some methods of heating your home are dangerous and should be avoided. Do not use a gas stove or oven as it could cause a dangerous build-up of carbon monoxide. Outdoor grills should be avoided for the same reason. Do not use fire pits to start any type of open flame inside the house.

Remember that all temporary heat sources should never be left unattended.