Cold Water DangersIT'S hotting up...temperatures are soaring, and the heatwave is going nowhere (for now). And so naturally, us Brits are desperate for ways to cool down. Not that we're moaning about the weather, of course! Nothing seems more appealing on a day like today - as temperatures reach highs of 30C - than plunging into a freezing cold lake, river or taking a refreshing dip in the sea. But, while it might seem a sensible way to cool off, experts warn it could prove deadly. Cold water shock is a common but rarely talked about condition, that is the root cause of many deaths from drowning. It's where the body is suddenly plunged into icy cold water - and can trigger a deadly heart attack. The RNLI warn the average temperature of the sea off UK shores is 10 to 15C - cold enough to trigger cold water shock. Professor Mike Tipton, author of the book Essentials of Sea Survival, has said: "If you are lucky enough to survive long enough to die of hypothermia, you have done very well. "Most die in the first minute of immersion. "The RNLI states on their website: "It's cold water shock that tends to kill people around our shores. "That's because when a person plunges into cold water their body experiences a number of physiological responses. Firstly, the skin temperature is suddenly lowered - one of the most "profound stimuli the body can encounter", the RNLI explains. It's advice states: "The responses tend to be short lived, but threaten survival. "One of the first responses, is the closure of blood vessels in the body. This basically means they narrow, meaning less blood can pass through. "The heart then has to work harder and blood pressure increases," the RNLI explains.