As the Christmas break approaches and the big freeze with police are warning young people not to risk their lives on Kirk Hallam Lake.
The warning has been issued in the hope of avoiding emergency services being called out to rescue youths who have ventured out onto its frozen surface.
In January two years ago two Kirk Hallam Community College pupils were rescued in a major operation involving police, firefighters and paramedics after ice they walked on to get to the island started to thaw.
Pc Louise Stevenson, of the Kirk Hallam Safer Neighbourhood Policing Team, said parents needed to educate their children about the dangers this Christmas to avoid tragedy.
“You do not know how thick the ice is and it only takes seconds but once you are in the cold water and your responses diminish you cannot get out,” she warned.
“We try to patrol regularly but cannot get there all the time so we are relying on people being sensible. Also, you may be putting other people at risk who risk their lives saving yours.”
Pc Stevenson also warned against litter beng thrown onto the frozen ice which could pose a threat to wildlife when the ice thaws and it sinks into the lake.
Kirk Hallam councillor John Frudd backed the warnings but said walking out on the ice had unfortunately become custom practice for young people.
“It is very dangerous,” said John. “If you go through the ice you will not come in the same place and you may not come up at all.”