Emergency officials are warning people to take precautions before heading outside as Calgary’s stretch of bitter-cold weather continues.

Environment Canada issued a warning for Calgary on Friday, saying there is an extreme wind chill value below –40 C.

The weather organization warns that "frostbite on exposed skin may occur in less than 10 minutes."

Calgary's cold snap continued Friday morning with a temperature of –28 C at 7 a.m. MT. (CBC)

Paramedics have responded to more than 20 cold-related emergencies since the Arctic air mass parked itself over the city, EMS spokesman Adam Loria said.

With the actual temperature not expected to get above –26 C on Friday, frostbite and hypothermia are the two main concerns.

“Different degrees of frostbite definitely if not treated appropriately could lead to limb damage, tissue damage or possibly down the road amputation,” he said.

People working outside need to take regular breaks indoors and stay hydrated, he said.

Drivers should also be sure to have emergency supplies — including blankets, extra jackets, gloves and collapsible shovels — in their vehicles in case they get stranded, Loria said.

“It’s always essential to have those items. It could save your life,” he said.