Firefighters tackled a fire at a student accommodation block on Station Road in Uxbridge.
Part of a communal kitchen on the first floor of the building was damaged by fire. Seven people left the building before the Brigade arrived. There were no reports of any injuries.
A London Fire Brigade spokesperson said: “This incident is a reminder of just how important it is to have working smoke alarms in your home. Smoke alarms fitted in the kitchen area raised the alarm.
“Smoke alarms give the earliest possible warning when a fire starts. We encourage everyone to have smoke alarms fitted in every room where a fire could start.
“It’s also a good idea to have a heat alarm fitted in your kitchen. Fitting a heat alarm in your kitchen will give you warning of an increase in temperature caused by a fire but will not be set off by cooking fumes.”
The Brigade was called at 1845 and the fire was under control by 1953. Two fire engines from Hillingdon and Hayes fire stations attended the scene.
The fire is believed to have been accidental and caused by an electrical event within the extractor hood.