The emergency call came at 7pm on Sunday. A 14-year-old boy, Daniel Halliday, had disappeared while swimming at Crosby Beach in Lancashire. For 15 hours rescue services searched the area. Finally, at 10am on Monday, they gave up.

Last year 28 people aged between 10 and 19 drowned in Britain. Of those, 22 were boys.¹

 "Open water may look safe and inviting especially on a hot day," says David Diggins of the Derbyshire Fire and Rescue Service. "But it can be very dangerous due to very cold water temperatures, hidden currents, fast-flowing water, hidden rocks, rubbish or debris, and water pollution that could make you extremely ill."

If the temperature of the water is below 15C it can make your heart pump more rapidly - particularly if you are hot when you go in. This leaves you gasping for breath, and more likely to swallow water.

The part of a teenager's brain that thinks about an action's consequences is very slow to develop. But, says the BBC's David Robson: "Parents can encourage the use of critical thinking... schools can also help children and young people learn to make better decisions."

In May the Department of Education recommended that all pupils "should know how to recognise risk and keep safe around water". Lessons in this are likely to become compulsory by the end of the year.

In 1979 an American academic, Ronald A Howard, came up with the idea of "micromorts" to measure the riskiness of different activities - one micromort being a one-in-a-million chance of death. Climbing Mount EverestThe world's tallest mountain, which straddles the borders of Nepal and China. Temperatures can drop to -60C. The first known people to climb the mountain were New Zealand's Edmund Hillary and the Sherpa, Tenzing Norgay. is rated at 37,932 micromorts, whereas riding a horse is just 0.5.

"The important takeaway," writes Reece Goodall in The Boar, "is that everything carries risk, and we need to figure out which risks are worth taking in order to make life worth living."

Could lessons in risk help?

Yes: "These skills that underlie our destiny can be taught," says psychologist Joshua Weller. This means helping teenagers to think things through and not be carried away by the excitement of the moment.

No: Some people are born risk-takers. Jumping into a river or lake is something they do just because it looks tempting, and no lesson is going to make them stop to think twice about it.

Or... Taking risks is an essential part of life, and people who are not prepared to do so will never get very far. As Reece Goodall says, you simply need to weigh up the pros and cons carefully.

Mount Everest - The world's tallest mountain, which straddles the borders of Nepal and China. Temperatures can drop to -60C. The first known people to climb the mountain were New Zealand's Edmund Hillary and the Sherpa, Tenzing Norgay.