A man was burned as he attempted to escape from a house that had been the target of an arson attack.
Firefighters from St Neots and Gamlingay were called to a blaze in Luke Street, St Neots, at about 6.15pm on Tuesday.
A spokesman for Cambridgeshire Fire and Rescue Service said: "Crews arrived to find a fire on the first floor of a property. Wearing breathing apparatus, firefighters used one hose reel to extinguish the fire and one positive pressure ventilation fan to clear the smoke.
"One male casualty was out of the property when crews arrived at the scene and required treatment for minor burns and smoke inhalation. He was taken to hospital by ambulance."
Crews returned to their stations by 9pm.
An investigation revealed the cause of the fire to be deliberate. Anyone with information should contact police by visiting www.cambs.police.uk to submit an online report or call Crimestoppers, anonymously, on 0800 555111.