can hedgehogs die from being dropped in a bathtub by a 2 year old?

I suppose anything is possible, but the hedgehog would probably be alright. Do you have any idea what temperature the water would have been? It shouldn’t be at very much risk of any kind of sickness if the water was warm. Even if it were cold, wild hedgehogs survive in the coldest of rains and throughout the winter regularly. If you are truly concerned, see a veterinarian.

Wow this definately is an interesting question! I am guessing the bathtub was filled with water since you ask about hypothermia. This is a plus in that it didn't fall onto a hard surface. Most mammals are good with getting wet. It might get a cold , so if you want to avoid that just make sure it is thouroughly dried...and let it rest. After all, hedgehogs do fine out in the wild in the rain, so I can't see why some bathtub water would be a problem.

Hedgehogs are actually quite good swimmers and probably, because they have spines rather than thick fur, they dry off pretty quickly. Keep him in a warm but airy place (don't wrap him up in towels but let him go into his haybox or whatever if he wants to) and he should be just fine. In the UK it's illegal to keep hedgehogs as pets and they survive just fine in our wet and chilly (native) climate out of doors and in all weathers (though I guess that they know of dry places to go when it rains and certainly bury themselves in piles of leaves in the winter).