Environment and Climate Change Canada has issued heat warningsfor much of southern Alberta and into southeastern Saskatchewan.

The federal agency says temperatures could reach 37 C this weekend in some areas of Alberta.

It says the extreme heat is expected to continue into early next week.

The warnings include the cities of Calgary, Lethbridge and Medicine Hat, as well as dozens of smaller communities across southern Alberta and Saskatchewan.

Residents and visitors are urged to take precautions such as rescheduling outdoor activities to the cooler hours of the day, taking frequent breaks and drinking plenty of water to stay hydrated.

Environment Canada says heat warnings are issued when high temperatures could pose an elevated risk of heat stroke or heatexhaustion.