MAPUG-Astronomy Topical Archive Staying Warm in Cold Weather

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by Mark Florian

It's said by some that we only have two seasons in Central Texas: Summer & January! Many years that's true. Every once in awhile though, we'll have a really cold winter for our locale and it will be made worse due to our humidity. I see people wearing plenty of layers, but they still report they're cold. After discussing the topic with a few club members, I decided to write an article to help make Winter observing more comfortable for those who don't like the cold weather as much as I do.

The most common mistakes I see people make are wearing layers of cotton on top, tight-fitting jeans below, and shoes that leave their ankles exposed causing cold feet. Layers are important, but they must be the right layers, made out of the right fabric, to get the most warmth from the bulk. Otherwise, you'll resemble Randy in the comedy "A Christmas Story". You won't be able to put your arms down and you'll still be cold. So let's start next to your skin.

In cold weather, you should never wear cotton next to your skin. That goes for ALL underwear & socks! The reason? Cotton doesn't hold in heat very well even when dry and it absorbs moisture, so once it's damp, the moisture conducts heat right through it. If there is any wind, you'll feel a chill, making it worse. Once it's wet, it takes forever to dry. So the layer right next to your skin should be a synthetic fabric, such as a treated polyester. These go by the tradenames: Capilene, Thermax, Coolmax and others. They come in various weights from light to heavy and various styles like crew neck short sleeve & long sleeve, V-neck, regular turtleneck, zip turtleneck and 'mock' turtlenecks . Since polyester is incapable of absorbing moisture, it won't lose its insulating properties when wet and will dry rapidly. To increase this effect, the mills who make the tradenames treat it with a finish to make it repel moisture so that it will transfer perspiration to other layers, keeping you dry next to your skin. Polypropylene was the first of these on the market several years ago, but I wouldn't recommend it today. When put in the dryer, it shrank to doll clothes and over time it would absorb body oils and not release them, so it would turn gummy. The newer fabrics won't shrink or absorb oils.

There actually is a natural fabric that will work next to your skin and women have known about it for a long time: Silk. It's extremely . . . well silky, won't absorb moisture and allows other layers to easily slide over it. It also feels great next to your skin. The warmth it provides given its weight is amazing. My grandfather used to say, "Stick to me boy & you'll wear silk drawers!" I think he was on to something.

So the first layer next to your naked body should be underwear made of either treated poly or silk. The second layer should be a long sleeve top, bottoms, sock liners for your feet & glove liners for your hands. These last two items should be lightweight to make room for additional layers. If you get cold easily, put on a short sleeve crew neck poly shirt on top of this layer. This will help keep your chest & back warm. The next layer could be a heavier layer of polyester, or a poly turtleneck, depending on the weather and your own comfort level.

For your outer layer, you can wear a sweater. For reasons discussed above, wool would be a better material than cotton. Wool will absorb moisture though and when it does, it will lose all of its insulating ability. It also takes forever to dry so don't allow it to get wet. Another idea for this outer layer is a fuzzy fleece pullover or jacket. They also have pockets, which is an advantage over sweaters. These are everywhere these days, made of polyester, won't absorb moisture and trap heat very well. Look for one that has large enough pockets on both sides to hold your hands with gloves on. My favorite is the pullover style with a large kangaroo pocket in the front. It's a great place to store things, and even has room for my big hands with gloves on. If you get cold easily, wear a poly or down vest underneath this layer. If this outer layer has a nylon shell on it, it will keep the wind from cooling you off. This outer layer can also be a nylon down jacket or a full length coat that extends below your rump. Realize that even down will lose it's insulating ability when wet or compressed too much. It needs room to puff out. Resist the urge to wear a cotton sweater or sweatshirt for this layer if you get cold easily as it's not very warm given its bulk. Finally keep in mind that this outer layer will need to be large enough to accommodate the layers beneath. You need space for trapped air in these layers and so you can move. Remember Randy?

Next, let's talk about your legs. If you layer up your chest well, but only wear cotton jeans, you'll freeze. Why? A couple of reasons. First, your rump & legs have more surface area than your trunk. Two, cotton doesn't insulate very well and the warm blood that leaves your core will loose its heat as it travels down your legs to your feet and back again, where your core has to warm it up again. You'll be alright for awhile, then you'll start to get cold and then you'll start to shiver. Third, once you reach this point, your body will constrict the blood vessels going to your legs & feet to maintain your core temperature, making the situation worse. Fourth, jeans don't block the wind. So what to do? Well it depends on how cold tolerant you are and how cold it's going to be. Silk bottoms under jeans is a first step. Adding poly bottoms between the silk ones and your jeans is another. Wearing flannel lined jeans is another option. Get them roomy enough so you can layer underneath them if need be. Or forget jeans altogether and go with nylon insulated bib overalls, like those you ski in. These have the advantage of covering your lower back when you sit or bend over, so that no skin is exposed. Or you can wear sweat bottoms made of fuzzy polyester and wear plastic or nylon raingear or snowpants over them. This combination works well because it allows you to move, it traps warm air, the nylon shell keeps wind from cooling you off, and the suspenders don't constrict your waist like a belt does. With your rump & legs covered like this, you'll be very comfortable for long periods of time and your feet will stay warm.

How to keep your feet warm? Well we layer them. First goes on a very light long sock made of either polyester or silk. Next goes on a heavier sock that will cover your calves. Pull it up over your bottoms. Next you need a shoe that is large enough to let you wiggle your toes and trap heat. If your shoes are too small for these layers, you'll compress the insulation making it less effective and your toes will be jammed together, so they'll get cold. Insulated after-ski boots work well as they also cover your ankles. Regular shoes leave your ankles exposed and you'll loose critical heat. Plus cold air always sinks and that's where your feet are. Whatever boots you decide on, don't over tighten them.

Let's move on up to your hands. Layering works well here also. Start with a lightweight poly or silk glove liner, then an intermediate glove if you need it and finally a ski glove. Don't make the mistake of trying to cram your hand with these additional layers on into a glove that's too small. Your hands will be cold and uncomfortable and then you will. You need airspace around your fingers to keep them warm. Since we have to focus, change eyepieces, turn on flashlights and such, many will want to use gloves. But if your hands get cold easily, insulated mittens with a nylon shell over them are warmer because your fingers are all together and mittens have less surface area by far exposed to the cold than gloves. Another tip for keeping your hands (and feet) warm is to apply a little greaseless lotion to them first. It'll act as an additional insulation layer. Matter of fact, you can do this to your entire body (including your back) if you get cold easily. A little goes a long way here, you don't want to be sticky.

Finally, we come to your neck & head. A polar fleece neck gaitor (it looks like a short, wide tube that's open on both ends) will cover your neck and prevent heat loss, which can be substantial in this area of your body. If you wear a turtleneck, pull it up all the way under your chin as a first layer over your neck then put the neck gaitor over it. For your head, there are many choices. If you get cold easily, you should wear a silk or poly balaclava then a ski cap or the hood from your jacket (if it has one) over it. A balaclava looks like a sock, sized for your head, with a oval hole in the side for your eyes. It covers your head, ears, nose, mouth and neck. Even a lightweight one will keep you very warm. I have one made of the same heavyweight fuzzy poly fabric as a jacket for when it's really cold. It's better than another layer of clothing because of the amount of heat you can lose through your neck & head. Stopping heat loss here keeps you warm everywhere else.

You'll have to experiment if you've never dressed this way before. You may find yourself too warm. Wearing these types of fabrics makes a BIG difference compared with cotton. If you're going out on a walk, you can get away with less, because your muscles will generate heat as you exercise. For non-aerobic activities, you might have to add a layer here or there.

Now that you're dressed right, here are some other things to keep in mind:

  • Astronomy is not usually considered an aerobic activity, though I have seen a few rare exceptions. If you start to sweat, unzip your outer jacket, take off your hat, peal off an outer layer, whatever it takes. The goal is to not sweat. You may want to remove a layer before you start setting up and then put it back on when your finished.
  • Don't sit on a metal lawn chair, bench or even an aluminum framed beach chair in cold weather without first covering the metal with an insulated stadium seat or blanket. Metal is an excellent conductor of heat and you'll lose lots of it from your rump. Remember that when you sit, you compress all the air out of your insulation layers covering your rump, reducing their effectiveness. Don't sit on the tailgate of a truck for the same reason.
  • For a quick warm up, sit on the hood of your car if it's still warm.
  • Don't hold onto cold eyepieces, even with gloves on, any longer than necessary. Heat will flow out of your hands right into them.
  • Bring something warm to drink in a thermos.
  • If your hands get cold easily, don't wear a metal watch or rings on your fingers, they'll conduct heat away from your body. Put your metal watch in your jacket pocket. Likewise no earrings, noserings, liprings/studs, tongue studs, eyebrow studs, _____ studs. Don't stick your tongue on any cold metal, it WILL stick! Lastly remove all alien implants before observing in cold weather.
  • If camping in a tent and there is any wind, use your car as a wind break. Better yet, pitch your tent downwind of the engine to take advantage of its radiant heat.
  • Eat well a few hours before so your energy reserves are full. Your body burns more calories in colder weather because it's constantly losing heat and it needs to maintain its core temperature.
  • If you wear metal framed glasses to see at night, they might give you a headache over a period of time in very cold weather as they draw heat out of your temples where they touch. To prevent this, obtain some 1/8 or 3/16 inch adhesive backed foam weather stripping and attach it to your frames where they touch the side of your head. Or you can use a flexible piece of heatshrink tubing to slide over the end. You don't need to shrink it in place as you'll want to remove it later.

Copyright © 2003 by Mark Florian. All Rights Reserved.
Commercial & For-Profit Reproduction Forbidden Without Express Written Permission.

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