The dangers of swimming in open water are being highlighted as people are tempted into rivers and lakes during warm weather.
Bedfordshire Fire and Rescue Service is warning open water can be cold and contain hidden hazards.
Area community safety officer David Lynch said: “Cold water shock causes deaths every year. Young people, even those who are strong swimmers, are unaware of the effect that it can have on their ability to swim in open water.
“On a hot day a pond, pool, old quarry or river might seem inviting, but the cold water shock it can cause means you would quickly become incapacitated and could drown.
He added “Young people need to look after their friends by not encouraging them to risk their life or put themselves into danger. They should also learn basic lifesaving skills and not tamper with or remove lifesaving equipment like lifebelts.”
In Bedfordshire there have been 9 deaths in rivers and open water over the past five years.