If there's a zero day, there's not a lot you can do. NHS got hit so bad because they were running very old Windows versions. A lot of embedded systems have no upgrade paths (MRIs running embedded XP should probably not be on the network at all).

Hospitals need full backup machines and with health care costs already through the roof, that will just add more. Even if you have all your order entry machines setup to not make external Internet connections except to update servers, one bad e-mail getting through and you could be in trouble.