William Petersen was briefly hospitalized after falling ill on the CSI: Vegas set

TMZ

TMZ reports the actor had a "had a scary situation" and had to be transported to the hospital via ambulance Friday after telling the show's director he needed a break. "It became clear he might've needed more than just a rest -- because we're told an ambulance was called on his behalf, and Bill was taken to a nearby facility," reports TMZ. The rep says it was mostly done out of an abundance of caution, but it was clearly serious enough to call. As to what led to the health scare ... WP's rep tells us his guy has been working nonstop long days for the past 12 weeks -- so this may have been a case of overexertion or exhaustion. In any case, we're told Bill's now out of the hospital and doing better."