Fire crews are tackling a blaze at a house which is split into four flats on Witton Street in Northwich.
Fire engines attended from Northwich, Winsford, Middlewich and Stockton Heath along with an aerial appliance from Lymm are at the scene.
The fire involves the first and second floor and roof space.
Crews are using breathing apparatus, two jets and an aerial appliance to tackle the fire from the roof and from inside the property.
A large fan is being used to disperse smoke from a neighbouring property.
One person has gone to hospital as a precaution with suspected smoke inhalation. It is believed the occupants are out of the property.
Road closures are in place.