I put one foot in the water and immediately have second thoughts about wading in wearing just my underwear. Pity I don’t have a wetsuit on hand. It’s freezing; I’d guess about 20℃. I take a glance around the edge of the water and my reticence is justified: there are clumps of snow by the rocks and one large hunk of ice that looks like the sort of sculpture you’d find at the Tate Modern.

But I’m still hot though: after all, it is 26℃ outside, and I have little beads of perspiration on either side of my temples. I dive in. It is like a shot of morphine to the heart. The relief is instant: who needs Red Bull when you can swim in glacial lakes in the height of summer? These dips cool you down, re-energise the system, alleviate pain and give you a new lease of life–welcome side effects when arriving at the halfway point of a six hour climb.