Olympic Triathlete Who Threw Up After Race Blames Heat, Not Dirty Seine Water

An Olympic athlete's spilling his guts on why he spilled his guts after a race ... blaming weather conditions after his race in Paris' Seine River -- NOT the water itself.

Tyler Mislawchuk -- the Canadian triathlete who went viral for all the wrong reasons when he hurled 10 times after racing Wednesday in the Triathlon -- says he's not used to such blazing hot weather.

ICYMI ... Mislawchuk's crossed the triathlon finish line and blew chunks within feet of his fellow competitors. Social media's non-medical diagnosis --  the polluted Seine -- but Tyler says that's not why he retched.

Mislawchuk's from Winnipeg in Canada ... and he's used to training in freezing cold temps -- not the low 80's.

Olympic officials pushed back the triathlon when Paris was hit with a torrent of rain ... much of which flowed into the Seine and sent E. coli levels skyrocketing.

Competitors in the women's triathlon groused about the gross conditions in the Seine ... with one calling that part of the race a "lottery." We're assuming she means finishing first is more luck than talent.

But Mislawchuk's not complaining about the H20 -- placing the blame squarely on his shoulders after falling to six place. He's also taking his viral puking moment in stride, posting a pic of himself with the caption, "No regrets, all in."