Why alcohol and a swim in cold water on a hot day can be a fatal mix

(dpa) – It's a sunny day and you wind up having a few drinks at a lake or by the sea. So long as you're not too drunk, it's safe to head out for a careful swim, right?

Health experts aren't so sure. In fact, you run a serious risk of a damaging shock to your system if you head straight into the cold water after drinking alcohol and soaking up some sun.

That danger is present even if the water is a balmy 20 degrees Celsius, say the experts from the German health education centre BZgA.

It may be hard to resist the temptation to enjoy a drink or two at the beach or lake, but medical experts warn that drunk people have been known to faint and even drown after being exposed to a shock from cold water. (Photo credit: Christin Klose/dpa)

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That's because the shock of the cold water could cause you to faint and, in the worst case scenario, drown.

The trouble is that your body struggles to respond to the cold as it normally would, given the level of alcohol in your blood, which raises the risk of a collapse.

The reason is alcohol is a diuretic, so it has a dehydrating effect, interfering with your body's ability to regulate its own temperature. And both alcohol and warm weather dilate the blood vessels, making it all the more likely for even healthy, young people to suddenly pass out in such cases.

All doctors will tell you it's best to take it easy when it comes to alcohol, but this is especially true in hot weather, whether or not you originally planned on heading into the water.

(Reporting by: Tom Nebe in Berlin. Editing by: Allison Williams)