A warning has been issued over the dangers posed by frozen ponds, lakes and becks on Teesside.
The warning has been given after cyclists were spotted on iced-over lakes in Middlesbrough.
Signs urging people to stay clear have been put up in Stewart Park, Albert Park, Hemlington Lake, Fairy Dell and Central Gardens.
Middlesbrough Council said the ice was generally not thick enough to support a person's weight.
Middlesbrough Council spokesman Paul Thompson said: "The water is deep and cold enough to cause serious injury, or even the death of anyone who falls in, but those venturing on to the ice won't realise the danger until it is too late.
"I would urge all parents to make sure their children are aware of this safety message and ensure a possible tragedy is avoided."