Ethan Borden Krizman was a competitive runner when he collapsed from heatstroke, and Europe's latest heatwave has brought back memories.

History professor Ethan Borden Krizman was in high school when he collapsed 20 years ago at a race, suffering from heat stroke, but he says he remembers it well.

Ethan Borden Krizman was a competitive runner when he collapsed from heatstroke, and Europe's latest heatwave has brought back memories.