The key to running and dressing in winter, especially the upper body, is to have a sense of hierarchy. Wearing several layers of clothes can not only retain the body's heat, but also let sweat through the clothes. Water vapor will go from the first layer (innermost layer) to the outermost layer, and then evaporate. Here are some suggestions on how to put on your upper body clothes.

Basic layer: The closest one should be man-made fiber, like (polypropylene) or silk. These materials can sweat and keep the upper body dry and warm. It is very important not to wear cotton-padded jacket as the base layer, because cotton-padded jacket is wet with sweat and will always be wet.

Insulation: The second or middle layer of a garment. If the temperature is MINUS 20 degrees Celsius, you need to wear this layer. This layer needs to continue to absorb sweat from the skin. It needs to keep some air to make you feel warm, and at the same time, it needs to be able to discharge some heat to prevent the body from feeling overheated.

Windproof/rainproof outer layer: This layer should play the role of windproof and waterproof (light rain and light snow), and at the same time release hot air to prevent the body from overheating and cooling down. It's best to have a zipper on this layer of clothes, so that you can pull up or unzip it at any time to adjust your body temperature.

Gloves: Up to 30% of heat can be radiated from hands. Therefore, it is very important to pack hands. Mittens are better when the weather is very, very cold.