(at around 13 mins) The water was freezing cold in the lake Sarah Grant Brendecke skinny dips in. She joked in an interview about it making her nipples hard which male viewers would no doubt appreciate.
Shot in four weeks.
The temperature peaked at well over one hundred degrees inside the cabin throughout the shooting of the movie.
(at around 1h 16 mins) The shot of the alien goo coming out of Amy's vagina wasn't in the original script.
The original script didn't open with Clarence Singer being interviewed.