Update: An air quality advisory issued on Thursday was cancelled Friday as the weather changed.
The advisory was issued for eastern Metro Vancouver and the Fraser Valley because of pollution as temperatures soared the past couple of days.
That created high concentrations of ground-level ozone, which is formed when pollutants react with the air because of sunlight.
The warning said people should avoid strenuous outdoor activities during mid-afternoon or early evening when ozone levels are expected to be highest, especially if breathing feels uncomfortable.
It said infants, children, pregnant women, those with heart or lung conditions, diabetes, or respiratory infections such as COVID-19 may be at elevated risk.