The layer-on-layer or the gives you the ability to regulate your clothes according to how strained get when the temperature shifts.
You can easily relieve one or two layers as you move, then add a warming shirt and scarf when you hit an extra armor if the temperature requires it. According to the layer-on-layer, you should wear underwear.
It should be tight on the body and be made of a functional material.
For example (synthetic), wool or a combination of both of these materials.
Its task is to heat yourself when transporting moisture away from your body.
Avoid wearing cotton clothes at the bottom because cotton is not heated when wet.
The middle layer should heat your body (wool is good) and it should also be a material that breathes.
Plus so that moisture can pass through it.
In addition, the outer shell of GoreTex or equivalent material. Best of luck.