The UK had many military hospitals in kit form instores at various sites during and after the 'cold war', it was reputed that Burtonwood had up to 10 in stock, remembering that most are tent cities.
Waddington in GW 1 had a large transit medical facility set up in the Mission Support hangar, with expansion of Nocturn Hall RAF hospital. Numerous other units where also activated from stock only requiring the deployment of staff from the US to the UK.
Read Duncan Campbell's book the 'Unsinkable Aircraft Carrier' detailing US forces in the UK during the cold war.