A heat warning has been issued for southern Saskatchewan.

Environment Canada is calling for temperatures above 30 degrees starting on Friday, with the temperature expected to reach 40 with the humidex. Night time lows are expected to sit around 16 degrees as well.

The humidex is similar to the windchill during the winter, but the humidex is a calculation that tells us what it feels like outside with the humidity. For example, while the thermometer says 30, it could feel more like +36 degrees.

Warning Preparedness Meteorologist Terri Lang says that heat warnings are issued when temperatures reach 32 degrees or more for two straight days.

"The reason those were put in place was because health studies found that people could handle a day of heat with no problem, but it was the extended period [that affected them the most]."

Lang reminds people to avoid outdoor activities during this hot stretch.

"Avoid the heat of the day if they can, that means not going out and working at 2 O'clock in the afternoon in the full bright sun in the garden type of thing. Try and get your activities done in the cooler parts of the day."

At these warm temperatures, fatigue, exhaustion, heat stroke, dehydration and dizziness are all possible. Keep the water close, use plenty of sunscreen, limit your time in the sun and pay close attention to those in your care.