Police in Lincolnshire have warned members of the public not to take risks by going onto frozen water during the cold spell.
It comes after officers received reports of youths cycling on ice and someone venturing onto a frozen lake in an attempt to rescue a bird.
Police said people should never assume that any frozen water is strong enough to hold their weight.
Officers said the potential to get into trouble on the ice is "extremely high".
A Lincolnshire Police spokesperson said: "Police advice is never to venture onto frozen water, either for fun, trying to skate, walk or cycle, or to attempt to rescue an animal.
"Now that it is the school holidays, parents are urged to remind their children of the dangers of ice and tell them never to play on frozen water.
"If members of the public come across situations which they believe to be putting people's lives at risk, them please call the police."