An extreme cold warning that was issued by Environment Canada on Thursday morning has ended but residents in southern Alberta are still being encouraged to bundle up if they have to go outside.

Environment Canada says cold Arctic air that moved into the area overnight and light winds have generated wind chill values near -40 in many areas.

The cold conditions present a great risk for people who are not dressed appropriately for the weather and the agency says certain groups, such as the homeless, people living in poorly insulated homes, people with medical conditions, winter sport enthusiasts, infants and seniors are particularly at risk.

Residents are reminded to dress for the weather if you have to go outside for a prolonged period of time.

Extreme cold warnings are issued when very cold temperatures or wind chill increases the risk of frostbite and hypothermia.

Officials with WinSport's Canada Olympic Park have announced that the closure of the ski and snowboard hill at the facility will continue through Friday because of the extreme cold.

They say they are hoping to resume operation on Saturday as high wind chills are not expected in the forecast for the weekend.

Other areas of the park, including the Markin MacPhail Centre, the Calgary Gymnastics Centre and Canada's Sports Hall of Fame are still open for visitors.

For the latest hill updates, check WinSport's website.

ZOOLIGHTS is also cancelled for Thursday but officials say they have come up with a way to keep visitors warm so they will be back on for Friday.

CTV Weather Specialist Kevin Stanfield says that you should avoid going outside if you can, but if you have to, you should ration your time spent and get indoors frequently to stay warm.

For more information on the Environment Canada weather warning, check the website.

For the full forecast, go to our weather page.