"Extreme Heat" seems to be 37-40 degrees Celsius which is bafflingly mundane to me as an Australian who grew up in rural New South Wales. We'd pack 30 kids and a teacher into an un-airconditioned classroom with just a ceiling fan and the windows open in that temperature. I imagine the buildings there just aren't built to support that heat plus the body height of hundreds or thousands of attendees?
I grew up in a humid city and summers were unbearable. Now I live in a dry climate and 30°C is pretty comfortable.