Environment Canada has issued its first, heat-related special weather advisory of 2018 for the City of Toronto, warning that temperatures could reach the low thirties by Monday afternoon.

A "warm and humid air mass" is moving into the region, according to the federal weather agency, posing health risks to infants, young children, older adults and people with chronic illnesses.

Toronto is expected to hit 32 degrees today with a humidex of 37 and a UV index of 9, or "very high." 

It could feel as hot as 40 degrees in some parts of Ontario, according to Weather Network meteorologists, and there is a possibility of deteriorating air quality, particularly in the GTA.

Extreme heat seekers are advised to drink plenty of cool liquids, dress for the weather and enjoy it while they can.

Temperatures are expected to be lower on Tuesday with a (still hot but far more comfortable) daytime high of 25 degrees.