Cold water shock billed as one of the biggest hidden dangers of summer
Surrey Fire and Rescue are warning of the risks of wild swimming
We're diving deeper into the dangers of open water as we reveal one child a week dies from drowning in the UK.
Safety experts say so-called 'cold water shock' can kick in within minutes when the water's 15 degrees celcius or lower.
That's pretty much the temperature of ALL rivers, lakes, and reservoirs in Britain during the summer.
A statement from Surrey Fire and Rescue said: "Drowning is a leading cause of accidental death in the UK. Never enter the water and attempt to rescue someone yourself.
"In Surrey we have many different bodies of water, large lakes and the river Thames. They should all be treated with respect - water can kill."
The Fire Service advice that you are aware of the following risks:
- Cold water shock kills. The RNLI encourage people to "float to live", fight the instinct to thrash and give your body a chance to breath.
- Take notice and obey of warning and safety signs
- Stick to proper footpaths, riverbanks and cliff edges can be unstable
- Water and alcohol/drugs do not mix. Plan your route home away from water. 26% of people who accidentally drowned in 2022 had alcohol and/or drugs in their system
- Going out on your own? Let someone know where you are going and when you aim to return
- Never enter the water to rescue your dog, who will rescue you? Most dogs manage to scramble out - some owners are not so lucky
- Never enter the water if you don't know how deep the water is, or how fast the current is
They also advice that if you are taking part in outdoor water activities, do so in a designated area and find out about local clubs.
Weather can affect the water so check forecasts and tides before you go out.
Wear a lifejacket and make sure it's right for you and the activity.
Keep in touch - have your mobile phone with you, tell someone where you're going and when you'll be back.
And children should always be supervised by an adult.
Julie is one of the founders of The Surrey Hills Adventure Company, or SHAC.
They guide wild swimming groups and introduction to wild swimming classes to help people in Surrey enjoy the local beauty safely.
She said: "If you're not familiar with the water that you're about to get into, there could be natural hazards, there could be trees and things below the surface if you're about to jump in.
"And also things humans have put in the water that you might not know about, there could be glass bottles or anything.
"So if you don't know the water that you're about to enter, that could be a risk as well."