Both Hospitals and Ships are off limits to enemy fire. They can move in either the combat or non combat movement phase but not in both. You could move your hospital out of an enemy occupied territory and keep moving once per turn until you have it where you want it. They never are lost. For example, when China has lost it’s last man simply move the hospital down to India or the Middle East where your Ally can use it.
Those particular 12 sided dice work perfectly because of the symbol on them to mark a 12. It looks like a red cross symbol. You can get a set of them here;
http://www.historicalboardgaming.com/Amerika-Custom-Dice-D12-x6_p_2142.html
The reason I started the game with hospitals already is because they would have had these heading into a war, not waiting until someone got shot to think of buying some bandages. Also, I didn’t want to take any money away from the game that could be spent on weapons. I thought that most players wouldn’t bother buying them because either they couldn’t afford it ( like China) or they would just rather buy tanks so it would be a waste of time to make the rule and buy the pieces.