As millions of Americans face record-breaking cold temperatures, authorities are reminding people of the dangers of frigid weather.
The U.S. National Weather Service calls winter storms "the deceptive killers."
Exposure to cold temperatures and winds can put you at risk for hypothermia and frostbite. Both are life-threatening health conditions.
Hypothermia happens when your body temperature drops below 35 degrees Celsius. Authorities say even those who survive hypothermia are likely to have lasting kidney, liver and pancreas problems.
But without a thermometer, how do you know if you are suffering from hypothermia? Officials say warning signs include uncontrollable shivering, memory loss, disorientation, incoherence, slurred speech, drowsiness and apparent exhaustion.
Frostbite is damage that extreme cold does to your skin and underlying body tissues. The National Weather Service says a wind chill of nearly minus 29 degrees Celsius will cause frostbite in just 30 minutes.
Frostbite often affects the extremities of the body - those areas farthest from the warmth of your core, such as fingers, toes, ear lobes and the tip of the nose. It can turn those body parts white and cause you to lose feeling in the areas.
Authorities say the best protection from the cold is to stay out of it.