Northumberland Fire and Rescue Service is warning of the dangers in and around open water.
People enjoying the fine weather may be tempted to cool off in rivers, lakes or the sea.
Alex Bennett, chief fire officer for Northumberland Fire and Rescue Service, said: “There are three main dangers to people entering open water: The cold, which can stop people in their tracks; currents, which are often undercurrents invisible from the water’s edge and can sweep even the most competent swimmers away; and a lack of information about what lies beneath the surface.
“These hidden dangers can be especially prevalent in rivers and canals, where there may be objects underwater that could harm swimmers such as broken glass, tins, weeds or abandoned shopping trolleys.”
Coun Dave Ledger, deputy leader of Northumberland County Council, said: “We would like to remind people of the dangers, so that they can take the necessary precautions to remain safe at all times.”