Sounds a crazy idea? Don’t knock it until you’ve tried it. The benefits of icy cold plunges have been known for centuries, even practised by the Romans in their famous bath houses. Science is now catching up, with evidence that regular cold showers can lift your mood, increase alertness, and improve your immune system.

A recent study from the Netherlands found cold showers could reduce the number of sick days people took.

The 3000 participants in the study were asked to finish their morning showers with a 30-, 60-, 90-second blast of icy cold water, or to shower as they usually did, for 30 consecutive days.

They found the cold shower groups were absent 29 per cent fewer days than people in the control groups.

“This is the first high-level evidence showing that cold showers can benefit your health,” says lead researcher Dr Geert Buijze.

Even though many of the participants initially hated the cold shower experience, they stuck it out. By the end of the study two-thirds of the people decided to continue with them, said Dr Buijze.

Want to give it a try? Ease yourself in with 10 seconds, then build up gradually. If you have a medical condition and are not sure you should have icy cold showers, talk to your doctor. People with weaker immune systems and serious heart conditions, for instance, should get their doctor’s approval first.