Firefighters are at Sunset Close in Freshwater, for the second time in 24 hours.
They have just stood down a response to fears of a chemical incident, after they were initially called to help a man with a “red substance” in his face.
Isle of Wight Fire and Rescue says there is no hazmat incident.
Last night (Monday) they were called to the same address, to reports of a fire involving a front door.
Police and fire crews called to the scene at 9:05pm found a smoke grenade in the letterbox.
A 53 year-old man was treated for the effects of smoke inhalation.
Police are also on the scene this morning, alongside two fire engines and a rescue tender.