Police have begun an investigation into how a 14-year-old boy received serious burns in Ellesmere Port.
Emergency crews were called to deal with a motorbike which was on fire, at about 0200 BST on Thursday.
An ambulance was called to a house on Beeston Green in the Little Sutton area and the boy was taken to hospital.
He is being treated in Alder Hey Hospital, where his condition is said to be serious.
Inspector Rob Woodward, of Cheshire Police, said: "At the moment we are making inquiries into a motorbike that was stolen half-an-hour earlier, that was recovered burnt-out.
"There was another juvenile with the injured boy. He has not suffered any injuries, but is obviously very shaken."