Warm weather may have you reaching for the sunscreen or a cold beverage – but it can also pose health hazards.

A smog advisory was issued Tuesday morning for parts of western Ontario.

Wednesday, that advisory expanded to include Waterloo Region, Guelph, southern Wellington County, Stratford, southern Perth County, southern Huron County, all of Norfolk County and all of Oxford-Brant, as well as areas further southwest.

According to Environment Canada, all affected areas are at risk of poor air quality Wednesday afternoon.

For the afternoon hours, Air Quality Ontario is forecasting a high air quality risk for Kitchener, Brantford and Guelph.

Children, seniors and people with cardiovascular issues are particularly at risk of symptoms including increased coughing, throat irritation, headaches and shortness of breath.