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.

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.