Southern Ontario is set to experience its first prolonged heat wave of the season, with temperatures expected to top 30 C through Canada Day and humidex values reaching the 40s. Environment Canada climatologist David Phillips tells Global News the combination of extreme heat, high humidity and warm overnight temperatures could increase health risks, particularly for vulnerable groups. He also explains how climate change is making heat waves more frequent, longer-lasting and more intense. For more info, please go to https://globalnews.ca Subscribe to Global News Channel HERE: http://bit.ly/20fcXDc Follow Global News on X HERE: http://bit.ly/1Toz8mt Follow Global News on TikTok HERE: https://www.tiktok.com/@globalnews.ca?lang=en #GlobalNews