Icy dips make you feel alive, but they can kill too

Humans have enjoyed a bracing dip for centuries – even the Romans had cold baths known as frigidariums.

But cold water can be either a health benefit or a hazard.

As your body enters the water, temperature receptors are activated.

This affects your breathing, causing rapid, “gasping” breaths.

Your heart rate and blood pressure will spike.

Blood vessels contract, so less blood can be pumped around the body, and less oxygen will reach your cells.

This strain on the heart and lungs can, in some people, prove fatal if submersion is done too quickly.

Even healthy young people can experience a heart arrhythmia – an irregular heart rate – in the first ten seconds.

It’s called the cold shock response, and in the UK they lose a child every week from it, and an adult every 30 hours.

That said, those who take the plunge regularly say it makes them feel more alive.

That’s partly because stress hormones cortisol and adrenaline are released in preparation for fight or flight.

They say they experience fewer illnesses, too, and less inflammation in the body.

One Dutch study found those who turned their shower cold for at least 30 seconds had 29 per cent fewer sickness absences at work.