Men’s Summit Bamboo Base Layer*, Bam, £49, bambooclothing.co.uk

Made from bamboo (68%), organic cotton and elastane, the Summit (above left) is supremely comfy. The thermal qualities are good when dry, and the half-zip helps you cool off when you need to. Bamboo fabrics are breathable with odour-resistant properties. They are also environmentally friendly, but combined with the cotton will absorb more water if soaked, reducing performance levels. Thumb-holes are included. VERDICT 7/10

*The closest equivalent for women is Bam’s Velocity Base Layer (£49, above right), which is made of a slightly lighter weight fabric.