My son died swimming in a reservoir in hot weather - parents must be aware of the dangers

A mother whose teenage son drowned after swimming in a reservoir during hot weather has urged people to stay out of open water, saying she does not want another family to experience the same heartbreak.

Maxine Johnson's son, Reuben Morgan, was 15 when he died on 17 June 2006 after getting into difficulty while swimming with friends at Pontsticill Reservoir near Merthyr Tydfil.

As Wales and the UK experience a record heatwave, she is urging parents to speak to their children about the risks of swimming in open water, particularly cold water shock.

"If that can happen to him, it can happen to anybody," said Johnson, who raises awareness about water safety in schools and community groups.

There were 202 accidental water-related fatalities across the UK in 2025, 85% percent of whom were male, according to the National Water Safety Forum. The real figure could be higher, however, as a "high number" of water-related deaths were not recorded or inconclusive.

Johnson said her son had been camping with friends when they decided to swim across the reservoir, but he experienced cold water shock when he was most of the way across.

Reuben's friends, one in particular, "tried their best to help", Johnson said.

"He told his friend to just go, basically because [Reuben] was dragging him down."

She said the boys reached the shore before looking back and realising Reuben had disappeared.

A major search operation followed, but it took three days for specialist teams to recover his body.

"The boys were in such shock they couldn't quite pinpoint exactly where he was in the reservoir," she said.

"That made it quite difficult because that reservoir is very deep and very murky."

At the time, Ms Johnson said neither the family nor Reuben's friends understood the dangers of cold water shock.

"None of us would have known about cold water shock," she said.

Amid this week's hot weather, Public Health Wales has urged people to follow water safety advice including not swimming alone, avoiding jumping into open water, supervising children, choosing lifeguarded locations, avoiding alcohol, and follow "Float to Live" advice.

Johnson said there was no phone signal where they were, so by the time emergency services arrived "it was much too late".

She said many people wrongly assume water is warm during periods of hot weather.

"In the UK the waters take quite a long time to warm up," she said.

"The diving team told me it was really, really cold in the reservoir that day."

For almost 20 years Johnson has campaigned to raise awareness of water safety, speaking to schools and community groups about the dangers of swimming in reservoirs, rivers and lakes.

She said recent reports of drownings across the UK had left her worried.

"It's really terrifying because there have been so many deaths across the UK and I would anticipate we're going to see more with the hot weather," she said.

Johnson said parents also needed to understand the risks and speak to their children about them.

"I think a lot of parents don't realise the danger is still there," she said, adding that many young people go into water with their parents' permission.

"They don't realise. They just think they're going to have some fun getting in the water.

Reuben was 15 when he died, and Johnson said he was "super fit", played rugby, loved the gym and had a large group of friends.

"He was such a lovely lad."

She said her son's strong level of fitness was why his death was such a powerful example of how cold water shock can affect anybody.

"People think if you're a good swimmer it doesn't make any difference, but if you don't know how to counteract the panic, cold water shock can affect anybody," she said.

"It's heartbreaking for me and the family when we know that children and young people are still going out there into open water.

"That's why I feel so passionate.

"I don't want other families to experience what we've experienced."

Cold water shock is the body's involuntary response to suddenly entering cold water.

According to Welsh Water, it can affect anyone regardless of their age, fitness or swimming ability.

The immediate effects can include:

• Gasping uncontrollably
• Rapid breathing
• Panic and disorientation
• Loss of control of arms and legs
• Exhaustion

Reservoirs can remain dangerously cold even during hot weather, as deeper water temperatures rise much more slowly than air temperatures.