Base layers

The base layer is what you wear next to your skin. It's important as it can help to keep you warm and also to wick away water from sweating.

Cotton is not particularly good as a base layer, although of course it's very common to have cotton T-shirts, polo shirts and underpants. The problem is that cotton absorbs moisture but then retains it. That cool soggy feeling may not be too bad on a hot day when you can strip off and let it evaporate, but it's quite a different matter when you have been sweating up a hill in winter and find yourself rapidly cooling as you rest at the summit.

Merino wool and similar fibres make excellent base layers, and there are an increasing number of technical fabrics that also do the job. Any outdoor shop will have a range of long and short-sleeved shirts and vests, as well as underwear.

For the summer you may want a floppier shirt that allows air to circulate and keep you cool. In winter you may choose a baselayer that is closer fitting and thicker. Either way the wicking effect will stop moisture building up in your clothing and overall you will be much more comfortable.