Skiing is an active sport which generates much body heat and perspiration while you are skiing. However as soon as you stop, this perspiration cools, condenses and you become cold. It is advisable to invest in clothing that is of a breathable nature.
NEXT TO THE SKIN:
Thermal Base Layers are required that wick moisture away from the skin; flat lock weave quick drying, lightweight, soft fit , and performance wicking are what to look for.
The middle layers should partly absorb and partly transport moisture away from the body while providing insulation and warmth by trapping air within. These are ski shirts and can be layered up to suit the conditions.
OUTER LAYER OR SHELL:
This should prevent moisture, cold and wind from penetrating to the body, while at the same time prevent condensation within the clothing by drawing out the moisture through the outer shell.
The insulation should be Thermulate B or Thermasoft - high density polyester with low loft, excellent durability and thermal properties to contain body heat and withstand subzero temperatures
Modern ski jackets of 'Tres-tex", 'Pile.Tech' shells; with 'ColdHeat®" "Pile.Tech®" insulation; along with 'Polyamide', 'Rapia' and 'Alumesh' linings have improved warmth and comfort for skiers even in sub-zero temperatures.
Manufacturers like Trespass now use a Fabric Rating System given to each style. Eg A 3000mm rating means a pair of ski pants is waterproof to a Hydrostatic head of 3000mm of water pressure and will have better quality fabrics, warmth and wind protection than a 2000mm rated jacket.