TORONTO -- Environment Canada has issued a humidex advisory for much of southern Ontario, with many areas under heat warnings as the stifling weather continues.

The agency says temperatures are expected to peak in the low to mid 30s.

With the humidity factored in, it will feel like 40 C.

People are asked to check on those such as seniors who are vulnerable to hot weather.

Cooler temperatures along with lower humidity are forecast for Tuesday.