Appropriate mountain gear
The weather in the Alps can change rapidly, so you should dress according to the onion principle and combine layers. It will keep you from feeling either overheated or underheated.
The base layer (for transporting sweat)
Thin, tight-fitting underwear made from merino wool (or polyester or propylene). You need it to keep sweat away from your body while keeping warm at the same time. Wool has the advantage of reducing odour.
Take a second shirt with you in case you need to change.
The insulation layer (to keep you warm)
Depending on the season, you may need one or several layers of wool or fleece. As a result of their fluffy fibres, they provide optimal insulation and trap air.
The outer layer (for weather protection)
The materials used are designed to keep out the wind and rain. Outer layer fabrics should be breathable so that water vapour can leave the skin. It is easy to recognize good quality jackets by their taped seams.