Cast and crew would pass out on set.
Simi Valley, California is about as hot as it gets in the United States. Actors and crew members were known to pass out from heat exhaustion thanks to their wardrobe and the unrelenting sun.
Karen Grassle had to change her name to land the role.
Michael Landon hated Karen’s stage name (Karen Tree) so much that he stipulated her getting the role with a change in her credited name. Needless to say, Ma obliged.