No-fear teenagers have been risking their lives by swimming in the Coronation Channel to cool off as Spalding bakes in temperatures up to 30C.
They have also been seen jumping into the River Glen at Surfleet from the bridge crossing the A16, in spite of there already being 12 deaths in waterways across the country.
The closest tragedy was the death of a 16-year-old boy in King’s Lynn, who drowned after being held under the water by reeds.
Temperatures are due to remain high this week and South Holland has been put on a Met Office Level 2 heat health watch.
With schools due to break up for the summer today, the Environment Agency is urging residents not to swim in rivers and waterways.
A spokesman said: “Swimming in rivers may seem like an attractive proposition during the summer, but fast currents, river weed, unstable riverbanks and underwater objects can pose a serious health and safety risk – or even result in tragedy.”
Lincolnshire Police has tweeted graphic images related to diseases caught in waterways – swimmers’ itch caused by snails and Weil’s Disease from rat urine.
Sgt Stuart Hurst said: “We are working with the Environment Agency to ensure residents are aware of the risks.”