The man in question has been rescued and taken to hospital after a first-floor flat fire broke out in Grosvenor Gardens, Boscombe.
They have yet to be identified, and a joint investigation is taking place between fire service and Dorset Police.
Ambulance crews were alerted whilst Springbourne, Westbourne and Christchurch fire departments responded to reports of a property fire just before 1:45am. Crews were supported by an aerial ladder platform from Westbourne.
After the individual was rescued, the fire was extinguished using four sets of breathing apparatus and two hose reels.
Residents and nearby homes were evacuated and the road was closed to let emergency services pass through.
The house is now cordoned off with Police cars stationed outside the home in Boscombe.
Fire Investigation Officer, Station Manager Shaun Milton said: “Firefighters were able to rescue one casualty from the building and he was left in the care of colleagues from South West Ambulance Service.
“The fire doors and detection systems without doubt saved many lives this morning. A joint investigation between DWFRS and Dorset Police, into the cause of the fire, will continue during daylight hours today.”