请密切关注天气情况,做足保暖措施,防止冻伤。 ; w' ]. G& B7 xA very cold Arctic airmass and winds of 15 to 20 km/h will generate wind chill values below minus 40 across much of Alberta tonight. Conditions will improve somewhat by Sunday afternoon as temperatures rise. " u6 [4 V) [- a9 M& g" q $ s! V' f3 l. r. c) jAt these extreme wind chill values frostbite on exposed skin may occur in less than 10 minutes.