How to Dress Warmly and Avoid Frostbite

The weather can change in minutes going from sunny and warm to cloudy, windy and bitterly cold. Dressing right and being prepared is the way to avoid frostbite. Wearing one big heavy coat is not going to keep you very warm in cold conditions.

How Your Body Loses Heat

Evaporation occurs when your skin gets wet either from rain, snow or sweating. As you start to dry you cool off.

Conductive cooling is when you are touching something cold, like cold metal. The cold object can draw the heat out of your hands and fingers.

Wind chill or heat transfer occurs when the wind draws the heat off of you. Wind chill is the temperature as it feels to your skin, and can cause frostbite quickly, especially on exposed skin.

Radiation cooling happens when body heat escapes from you. This usually happens because you are not dressed properly.

Wind Chill and Frostbite

Wind chill is a big factor in getting frostbite. It could be 5 F above zero (-15 C), but if the wind is blowing at 20 mph (32 km/h), the wind chill temperature is –15 F (-26 C). The wind chill temperature is what your exposed skin will think the temperature is. With a wind chill of –19 F (-28 C) or lower, your exposed skin will get frostbite in 30 minutes. Wind chill is very dangerous on cloudy days and especially at night.

Dress in Layers

Layers create more insulation, trapping your body heat in and keeping out the cold more effectively. Dressing in layers lets you take off a layer or two if you get too hot, and put the layers back on if it gets cold again. How many layers you wear, depends on what your activity is and weather conditions. These layers should be loose fitting, not skin tight.

The first layer next to your skin needs the ability to wick away moisture. You can sweat a lot in frigid temperatures, and clothes that stay wet will make you much colder. Do not wear cotton next to the skin, it will hold in the moisture and stay wet. This layer should be made of silk, polyester, poly blend and synthetic material with brand names like Powerdry, Coolmax, Capilene, Dryskin, Thremax and Tremastat.

The next layer can be a t-shirt if you are going to have a third layer before your coat. This middle layer can also be Polartec® polyester fleece, pile, merino wool or a sweatshirt. Another middle layer under your coat can be a down vest or a vest with Thinsulate™. Down is excellent in dry conditions, but will lose its insulating properties if it gets wet.

Coats. Today there are many materials that are used for coats. Thinsulate, as the insulator will be very good and lightweight. Thinsulate comes in different weights. The lower the number (in grams) the less insulating it is. A fall jacket might have a Thinsulate weight of 40 g, while an arctic jacket would have a weight of 200 grams. Gore-Tex® is a good water resistant material. Other materials can include Scholler®, Thermolite, polyester mesh and nylon. Stores like Lands End rate their coats by temperature as well.

Other insulating materials for sweaters, socks and coats to look for are Lamilite, Primaloft, Exceloft, Thermoloft, Termolite, Polarguard, Holofil, Lite Loft, Miroloft, Quallofil, Lamilite, and Thinsulate.

Wear a hat since as much as 30% of your body heat can escape through your head. Make sure it can cover your ears. Materials for a good hat can be made of synthetic materials such as acrylic knits or Windstopper ® polyester hats. You can also choose wool with a liner.

Cover your face. Your face and nose are susceptible to frostbite. You can get a ski mask or a balaclava that will cover your face and neck. Made from various materials that will wick the sweat away and keep your face warm. Materials can be thermafleece, fleece, polyester and merino wool.

Gloves are very important. Frostbite will usually affect the extremities first. Gloves are better where you need to use your hands and mittens are warmer. You could put a pair of mittens over your gloves and remove the mittens when you need to use your hands. Gloves with a Thinsulate lining are good. Gloves should also be water resistant. Gloves might be better bought in person instead of over the Internet so you can make sure they fit properly.

Socks should be warm and able to wick away moisture and keep your feet warm when wet. Feet can sweat and you are usually stepping in wet snow. Never wear cotton socks. Materials like wool or nylon are good. Wool with a silk lining is good; or synthetic wool with the brand name of SmartWool, with a lining, is good.

Boots should be breathable and waterproof to keep your feet warm and avoid frostbite. Boots can be insulated with Thinsulate or other material with ratings to –40 F and lower. Boots and socks shouldn’t be too cramped; you want the blood to flow properly to your feet and toes. Stay dry, getting wet is a quick way to get frostbite.

How you dress will depend on your activities from walking the dog, shoveling snow, skiing or sitting at a football game. That is why layers are so important to avoid frostbite. Also realize, your dog can get frostbite as well.

© 2009 Sam Montana

Sources

Photo Courtesy of Creative Commons by Elisfanclub on Flickr

Wind Chill Chart

SierraTradingPost.com

REI

Lands End