Of the 7 German soldiers in the search team, one has 3 chevrons pointed down (HauptGefreiter) and 1 has 2 chevrons pointed down (Gefreiter). The one with 3 chevrons is seen as a camp guard in several other episodes without the chevrons.
The sequence where Carter, Newkirk, and Kinchloe throw hand grenades to blow up the water works in Hamelburg was originally used in Sergeant Schultz Meets Mata Hari (1967) - except it was a high velocity shell factory then.
Sergeant Carter (Larry Hovis) has to be lowered into the well, which is filled with icy water, to retrieve the stolen code book. Body heat is lost much more quickly in water than in air, which could cause hypothermia, where the body core temperature falls below 35.0 °C /95.0 °F. This can be fatal if exposure lasts too long.