Crews were called to Church Street at around 10.37am after a fire broke out at a flat.
Four appliances from Hartlepool, Billingham and Stockton attended the incident, which caused 100% smoke damage to the flat and fire damage to the floor and the wall of the property.
Firefighters used positive pressure ventilation, one jet and two breathing apparatus to deal with the blaze.
Crews left the scene at 11.48am.
No injuries were reported.