UPDATE: All heat warnings in this story have ended.
Environment Canada said a prolonged heat event starting Wednesday in Saskatchewan will last into the weekend.
Most of Saskatchewan is under a heat warning as a building ridge of high pressure over the province will bring daytime highs into the 30s.
Some parts of the province could break record high temperatures over the coming days.
Overnight lows will be in the mid-teens.
Environment Canada said there will be a reprieve from the heat on the weekend when cooler air moves into the province.
Officials are cautioning people to watch for the effects of heat illness: swelling, rash, cramps, fainting, heat exhaustion, heat stroke and the worsening of some health conditions.
People are advised to drink plenty of water even before feeling thirsty and to stay in a cool place.
Older family, friends and neighbours should be checked on to ensure they are cool and drinking water.
Anyone working outdoors should take regularly scheduled breaks in a cool place.
Anyone looking for advice on health risks, symptoms or precautions associated with heat-related illness should contact the Saskatchewan HealthLine at 811.