The body of Alfie McCraw, from Wakefield, was found after a search in the water after he was reported missing on Monday afternoon. Superintendent Nick Smart said: “This was an extremely tragic incident which resulted in the loss of the life of a boy who had just finished his GCSEs. “We have specially trained officers supporting Alfie’s family at this unimaginably awful time. “We are working with the Canal & River Trust to get some input into schools before they break up for the holidays to warn about the dangers of swimming in the open sea, but we need everyone to help us spread this message. He added that the force is urging people “not to be tempted to cool off in open water unless it is a supervised swimming area”. Emergency services have also issued reminders in recent days about the dangers of open water, which can be very cold meaning people may be more susceptible to hyperventilation. The Canal & River Trust warns on its website that there are also hidden dangers of open water swimming, including submerged debris, reeds and unexpected cold water shock. The news comes amid warnings of rising temperatures in the coming days. The Met Office issued a “rare” orange weather warning for most of England earlier this week, suggesting the nation could see “exceptionally hot temperatures”. Wakefield Station Commander Jimmy Fitt said: “When the warm weather comes we see a sharp increase in the number of people entering the water – and unfortunately this can prove fatal. “Our advice is not to go into any unsupervised areas of the water – as the drag of the water, cold water shock and hidden dangers can mean even strong swimmers struggle.”