Louis Mandylor -- best known for his role as Nia Vardalos' brother in "My Big Fat Greek Wedding" -- is lucky to be alive after collapsing on the set of his new movie.
Mandylor was shooting scenes in 90+ degree heat Tuesday for the movie, "Daylight's End" ... when he became ill and was rushed to a hospital in Tyler, TX.
Doctors diagnosed the illness as heat exhaustion and dehydration -- which affected Mandylor's kidneys.They're saying kidney failure was on the horizon ... this according to Mandylor's people.
He's expected to recover and should be released from the hospital Friday.
'My Big Fat Greek Wedding' Actor
Near Death Illness
7/24/2014 10:53 AM PDT BY TMZ STAFF
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