Plunging temperatures wreaking havoc across the US and Canada can lead to frostbite on bare skin in only five to 10 minutes, experts are warning.
A powerful Arctic winter storm has placed more than 135 million people under weekend weather alerts ahead of the busiest travel days of the year.
The alerts stretch from coast to coast and reach as far south as the US-Mexico border and Florida, the Sunshine State.
Major airports have canceled thousands of flights as the storm intensifies. The cold snap could bring the iciest Christmas in decades, say, forecasters.
The National Weather Service (NWS) said temperatures of -50F (-45C) and -70F were possible by the end of this week in some parts of the country.
Frostbite is caused when blood flow to the extremities is reduced – a natural response to the cold. Symptoms usually begin with the affected parts feeling cold and painful. In extreme cases, the tissue can die and surgery – even amputation – could be necessary. Someone with frostbite should be taken into the warm and medical advice sought
