HOW TO BUY BASE LAYERS

Collar

A high zip-necked collar is ideal for year-round use. In cooler months, it keeps you warm and in summer the zip provides good ventilation. Crew neck might be more comfortable though. If you opt for a zip, look for a garage at the top, as they can irritate the skin.

Fit

To wick sweat effectively, base layers should be worn next to the skin and be closefitting throughout. Look for flat-locked seams to avoid chafing. More length in the body is good in cold weather so you can tuck it in, helping to retain body heat.

Sleeves

Short sleeves are cooler in summer but long sleeves are probably a better all-year option. They protect against sunburn in summer and keep you warm in the cold. Some have thumb loops – make sure the sleeves are long enough to stay comfy if these are present. Cuffs should fit closely enough to keep out cold draughts but be easy to pull up when it’s warm.

Material

This is the most important thing to take into account. That old adage ‘cotton kills’ is right – cotton is absorbent and doesn’t insulate well when wet. It will hold onto moisture (be it rain or sweat) for a long time, which can make you dangerously cold. Plus, it chafes. Much better are synthetic fibres, wool or silk. Synthetic fibres tend to be excellent at wicking moisture away but can also quickly become smelly and are sometimes scratchy. Some contain treatments, often silver chloride (Polygiene) or carbon to combat the smell. Merino wool is naturally antimicrobial, so you can wear it for longer before it starts to smell, generally feels softer next to the skin and is excellent at regulating temperature, but it doesn’t dry as quickly as some other fabrics. Often, base layers feature a mix to get the best of both.