A man has been injured after he challenged a group of youths throwing snowballs at passers-by in Swindon.
Police described the incident which happened at about 1630 GMT on Monday in Farringdon Road as a serious assault.
The man was taken to hospital for treatment after he suffered a fractured eye socket when he was punched.
Det Con Neil Hilton, from Wiltshire Police, said: "If people are being raucous in the snow, don't take matters into your own hands, contact us."
Police said the man was punched three times in the head after he tried to intervene as the gang threw snowballs at people in the street.
He received three fractures to his eye socket which will require surgery.
Officers are asking anyone who has information about the incident to contact them.
They said they would particularly like to speak to a couple who were also targeted by the youths.