Where do you get this block of ice? (Admittedly pretty easy to acquire/make if it's smallish.) And where would the students get their electric gadgets?
Assuming you took a truck hunting, get rid of the problem altogether. Stick the meat in the freezer and stick the freezer in your truck and take it home with you where you can not only monitor it personally, but still enjoy the meat whenever you want. The only concerns then are keeping the freezer interior cold enough for the trip back (pretty easy) and the space at your place.
Assuming you took a truck hunting, get rid of the problem altogether. Stick the meat in the freezer and stick the freezer in your truck and take it home with you where you can not only monitor it personally, but still enjoy the meat whenever you want. The only concerns then are keeping the freezer interior cold enough for the trip back (pretty easy) and the space at your place.