Schneider, 42, was filming the comedy "Big Stan" at a women's prison near Stockton, about 80 miles east of San Francisco in the San Joaquin Valley where temperatures have soared above 100 in recent days.

"The combination of bad food and the heat just hit him," said his publicist, Shara Koplowitz. She did not know what he ate but said he was treated at San Joaquin General Hospital and released Wednesday.

"He's back on the set directing today," she said Thursday.

Firefighters were called out to the set for several cases of heat exhaustion since the movie shoot began earlier this month, said firefighter Michael Olizas with the Montezuma Fire District.

Schneider, who recently starred in "The Benchwarmers" and "Deuce Bigalow: European Gigolo," is directing the new movie in which he plays Big Stan, a con man locked up on fraud charges who learns kung fu to defend himself against other inmates.

(Copyright 2006 by The Associated Press. All Rights Reserved.)