Firefighters from Newmarket and Soham were called to tackle a fire at a derelict building in Soham on Saturday.
The incident took place at a two-storey derelict house in Paddock Street at around 11.30pm.
Breathing apparatus and hose reels were used to put the fire out. Crews returned to their stations by 1.25am.
The fire is believed to have been started deliberately.