THUNDER BAY - A heat warning has been issued for the Thunder Bay region.
Hot and humid conditions are expected Sunday through Tuesday.
A hot and humid air mass will affect areas of northern Ontario.
Daytime maximum temperatures will range from 30 to 35 degrees, with humidex values above 36.
Cooler temperatures and lower humidity are expected by Wednesday with the passage of a cold front.
The risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.
