field hospital
From Longman Dictionary of Contemporary Englishfield hospitalˈfield ˌhospital noun [countable] a temporary hospital for soldiers that is near where the fighting isExamples from the Corpusfield hospital• She says they've set up a field hospital with the latest equipment.• But some are now recovering at an emergency field hospital.• Let's hope he is able to get in some training at his field hospital so that he at least stays in touch with his fitness.