A faulty fridge is believed to have been behind Saturday night's blaze at Chesterfield Royal Hospital.
According to a report by the Derbyshire Times, the fire started inside a drinks refrigerator located in a newsagent's shop on the site. Eleven fire crews were called to the scene and took around four hours to get the blaze under control.
The alarm was raised after an automatic detector inside the hospital was triggered at 9.20pm. Staff reacted quickly and the hospital's Accident and Emergency department was closed. A number of patients were transferred to other hospitals in the area.
Eric Morton, chief executive of the Chesterfield Royal Hospital, said his staff and members of the emergency services had "worked incredibly hard to ensure hospital services were minimally affected".
He said: "There is extensive damage to some areas but we will work as quickly as we can to repair this.
"We hope to have services back up to full strength within the next couple of days - albeit with some longer term reconstruction."