Heat Warning for Toronto and GTA
Heat warning may last several days and persist through Friday.
Warm front caused hot, muggy conditions, triggering an extended heat wave.
Extreme heat is a leading cause of death globally, urging hydration and checking on at-risk neighbors.
Pearson International Airport's record high is 38.3°C from 1948.
Canada Day high is 36°C with humidex near 48, risking worsened air quality.
Conditions improve by next week with lower humidity and daytime highs in 20s.
Excessive heat expected to subside after the weekend.