I don't know which idiot doctor(s) said that AC is necessary to prevent ogre from dehydrating, however the truth is
"A common cause of dehydration in the modern workplace is air conditioning, which causes a low water content in the atmosphere, leading to increased water loss from the lungs and through the skin. A lack of adequate hydration at work can cause symptoms such as tiredness, loss of concentration and headaches."
It is necessary that he is provided natural climate to recover and become a human again from an ogre.