First understand that garments may be waterproof or water resistant. A plastic raincoat or heavily waxed cotton garment such as Barbour or Aussie drover coats are waterproof. But the 'inside' flaw is they trap body perspiration and create your own wet microclimate. A water resistant garment will have a degree of repellancy and venting of body heat and perspiration. This is what GORETEX is claimed to do, and doesn't. It comes down to a tradeoff and what you need and for howlong and how severe. Sometimes that need is a big old tent with hot chocolate brewing on the stove.