It was a crushingly hot afternoon. My husband Bill and I were walking with our Swiss friends, Nika and Rubik.

It was June, and Europe was in the midst of a heatwave. The temperature in Zurich, the city we were visiting, was over 100 degrees.

As we staggered along, seeking one shady spot after another, Nika eyed us with a sidelong glance and asked: “Would you like to try something fun and unusual that local people love to do here during summer?”

Few buildings have air conditioning in Switzerland, and I looked longingly towards the snow-capped Alps. We nodded. Nika smiled enigmatically.

We found shade along the Limmat river which flows through the heart of the city.

The river has a strong current and is emerald green, but very clear. We came to a straight section with small wooden cabins along our side.

I blinked as I saw heads and arms bobbing in the current and heard the sound of laughter and splashing. Rubik showed us to individual cabins, handed us towels from his backpack and we quickly changed into bathing suits from ours.

When we emerged into the brilliant sunshine, Rubik did not hesitate. He jumped off the high walkway straight into the Limmat river!

Bill followed in an instant. I teetered on the edge, closed my eyes and leapt out into space!

When I hit the water the cold was absolute, and my chest contracted as I held my breath. I came to the surface tingling and slightly numb, and I was smiling as Bill let out a wild whoop of surprise.

The three of us were quickly floating downstream. Nika waved from the bank. My whole body felt so alive and awake, and a feeling of relief rolled through all my senses.

It was then I decided I would try to discover something like this I could do every day.

This is what I found: take a “contrast shower” in the morning. At the end of your usual hot shower, turn the taps to cold and stand under the bracing stream for at least fifteen seconds — more if you can.

Eventually, try a full minute or two. It is just fantastic! It rejuvenates, energises and makes you feel like a million dollars.

When I do it, I often remember how we jumped into the Limmat or through a hole in the ice after a sauna in Siberia.

It is a similar feeling. Your body comes fully awake in an instant, and you face the day with clarity.

Small steps, my dear readers, lead to long journeys!

• Nina London is a certified wellness and weight-management coach. Her mission is to support and inspire mature women to make positive changes in their body and mind. Share your inspirational stories with her at www.ninalondon.com