Dunked in the ocean. There just isn't a ton of plasma and it's not very good at transferring heat to things it isn't being pressed up against. So heat shields a

Dunked in the ocean. There just isn't a ton of plasma and it's not very good at transferring heat to things it isn't being pressed up against. So heat shields and the like function very well. Seawater by contrast gets everywhere, and if it does even a little damage, keeps doing it for a long time.