A base layer shirt is the foundation of any outdoor layering system. Choosing a breathable t-shirt instead of a material such as cotton means that the shirt can manage your body's moisture and perspiration more efficiently and keep you comfortable on your hike.
The range of Rab® men's base layer tops will help to keep you cool on warm days and will dry quickly when wet. Combine your breathable t-shirt with an insulating midlayer such as a fleece jacket under your waterproof during winter to ensure your body warmth stays where it needs to be. The theory behind the outdoor layering system is that it is much easier to layer up or remove layers to manage your body temperature than it is to cool down or warm up by simply using thicker or thinner items of clothing. When your layers are working in harmony together, it makes for a much more comfortable expedition. Combine your baselayer shirt with a pair of base layer pants to create a complete insulating base layer set for additional warmth.
Related: All Base Layers