Eight fire engines and more than 60 firefighters were called to the Radisson Blu hotel in Bath Road shortly after 4pm, according to London Fire Brigade.
According to the brigade, the hotel’s ground-floor sauna and plant room were destroyed.
In total, about 200 guests and 120 left the hotel before the fire brigade arrived, and there are no reports of any injuries.
Crews from Hayes, Feltham, Hillingdon and other neighbouring stations were called at 4.12pm and the fire was brought under control by 6.13pm.
The cause of the fire is under investigation, the brigade added.
