Here's another quality tech tip from senior refrigeration and HVAC tech Jeremy Smith. Jeremy lives in Ohio, so he knows a thing or three about the cold.

As HVAC/R techs, we're often called on to work in some of the worst weather conditions. With the cold weather, I thought it timely to share some tips and strategies that I use for staying warm in the cold weather, particularly for you guys in the south who think that 40°F is ‘cold.’

Staying warm, particularly in very cold weather, isn't about having the thickest jacket or the most socks; it's more about picking the right layers to wear. Let's be honest; we're all tough enough to gut out an hour or so in the worst conditions imaginable with a hoodie and a beanie cap. But when we're exerting that much mental effort just to endure being cold and miserable, we're not exerting that effort to work on solving that problem or making that repair. So, staying comfortable is both to our benefit and our employers' benefit, as we're more effective when we're not standing there shivering.

The first and foremost rule in staying warm is to stay DRY. Wet clothing, either from your own sweat or from rain or snow that melts into your gear, doesn't insulate as well. Some fabrics, like wool, retain their insulation better, but if you get wet, you're going to have a long, cold day. Let's start with what's called a “base layer.” The base layer isn't about insulation; it's about staying dry. Under Armour is a popular brand, and their stuff is great, but I go in a different direction and use Merino Wool base layers. They can be cheaper than Under Armour and perform at least as well. These aren't Grandpa’s itchy wool long johns; they're very comfortable, warm, and they help keep your skin dry, which is really the secret to staying warm.

Next, you want insulation. Fleece is good here—so is a nice Under Armour hoodie or similar item. Even a nice, thick sweatshirt is enough to keep your body warm. A vest is also helpful because keeping your body core warm is more important than keeping your arms warm. I've also got fleece pants for when it gets really cold, but I normally don't need them for work—layer one or more on as needed for conditions. On top of all of this is your outer shell. This is the wind and water-repellent layer. As HVAC/R mechanics, we need this layer to be abrasion-resistant as well. Something like a down ski jacket is probably the warmest thing you can find, but they won’t last very long around those sharp sheet metal edges.

A Carhartt coat and bib overalls are great and are the standard for tradesmen everywhere, but other brands like Walls and Dickies are just as warm and can be had for less money. Personally, I prefer a bib and coat set over a set of coveralls. That way, I can wear just what I need rather than having to either be cold or wear the entire heavy setup and maybe overheat.

Another nice thing to have is a foam kneeling pad. Not just to cushion your knees from the roof but to keep snow from melting into your insulation and making you colder.

Now let's talk headgear. Sure, a beanie is great, but when you've got to be out there for hours, you've got to keep the grey matter warm. My setup starts with a polypropylene fleece balaclava. They're great because they are so versatile. They're everything from a neck warmer to a full head, face, and neck insulator. Every tech that works in cold weather needs one. When the wind really kicks up, or the mercury really drops, though, that just isn't quite enough for all-day comfort out on that roof. Enter the “Mad Bomber” hat. Big, floppy rabbit-fur ears wrap the sides of your face and buckle under your chin. Now, we're staying toasty. When the weather really gets nasty, and the wind is howling, I'll pull the hood of my coat up then wrap a pair of inexpensive ski goggles over the whole mess. The hood keeps the wind off of the back of your neck, and the ski goggles protect your eyes from both the harsh snow glare and cold winds, and they hold the whole thing together. Best of all, ski goggles don't fog up as regular sunglasses do.

No matter how cold it gets, I don't like insulated boots for work. If I'm working inside, my feet get wet, sweaty, and uncomfortable. Then, if I have to go outside, I'm already wet. Once you're wet, you will get cold a lot faster. So, I stick with uninsulated boots for everyday wear, and I carry two extra pairs of socks. A pair of polypropylene liner socks is a good base layer for your feet. They're not for keeping you warm but for keeping you dry. Over those, slip on a pair of nice, thick wool socks. Lace your boots up over them, and you'll be plenty warm, but there is one more step to warm feet. Spend enough time out of the roof like this, and one thing happens: your boots get all snow-packed, then the snow melts and soaks through the boots, and you wind up with wet, cold feet. The answer is to wear a pair of overboots. Pull them on over your boots, buckle them up, and now your feet stay dry and warm. One quick note on boots: OSHA requires safety toe boots, but that doesn't mean steel toes. The steel toes on those boots just stay cold, no matter what you do, and it radiates what heat you've got in your toes, and you suffer.

When boot shopping, buy safety toe boots with a composite toe. The plastic safety toe is still OSHA-approved, but it's more comfortable to wear in the cold. One important thing is to avoid cotton. Cotton socks, cotton underclothing, etc., absorb moisture and don't provide any insulation value.

Unfortunately, I don't really have any all-day stay warm tricks for your hands. Wearing a pair of Ragg wool gloves is about the best protection I've found. Usually, I wind up with my hands in and out of the gloves all day, balancing between keeping my fingers warm and being able to do the job. Another nice thing to have on hand, so to speak, is a couple of packages of those disposable hand warmer packets. Unwrap one or two, and throw them into your pocket. Cheap-guy trick for those: if you're only out in the cold for an hour or so, seal that handwarmer up in a ziplock and press the air out. Since they're air-activated, removing the air stops the reaction. Open the bag back up, shake it up, and it'll start warming back up again.

In practice, this is how I'll employ this layering system. Your situation may be different. I dress for work very much the same every day: work pants and a T-shirt. As the weather cools, I'll add a sweatshirt and, eventually, a vest. That's just for walking around. When the call drops that I have to go hang out on the roof, I find a place where I can change. Based on experience in the cold, I'll select the right amount of layers to keep myself warm without overheating. Sweating can be as bad as shivering and will ultimately lead to shivering. I keep the heavy gear packed in a big duffel bag in reverse order of putting it on, so I can just pull a piece out, put it on, and grab the next piece. Peel gear off in the same order, and it packs away, ready for next time. If your gear gets wet, be sure to dry it before venturing back out into the cold.

Hypothermia and frostbite

Since we generally work alone, we really need to learn to self-monitor for these two conditions. Hypothermia is a serious, potentially life-threatening condition where the body's core temperature drops below 95°F, and the body is no longer able to warm itself. Your brain and vital organs will stop working, and you will go to sleep one last time. The first symptoms of this are violent and uncontrollable shivering. This is your body working your muscles vigorously in an effort to generate heat to keep itself warm. Further symptoms include slurred speech and disorientation. Don’t ignore these symptoms, and if you find yourself in that condition of violent and uncontrollable shivering, get yourself someplace where you can warm up and stay there until you are warm.

Frostbite is the formation of ice crystals in your body. This occurs when areas of exposed skin, typically fingers, toes, ears, and noses, literally freeze. It is very painful and can result in the loss of flesh in the affected area. Symptoms include pain, itchiness, and discoloration of the affected part, which progresses to hardening as the flesh freezes deeper. Much like hypothermia, this is much better treated early than allowing it to progress. Stop and allow the area to warm slowly. DON’T RUB IT. This breaks up any ice that has formed, and those ice crystals can cause more tissue damage. Cool water is the best way to warm a frostbitten area. One last caution or two to touch on:

A lot of guys like to drink coffee, tea, or hot chocolate to warm up. While I love a good, hot cup of coffee, this isn’t always the best way to warm up. Caffeine is a vasoconstrictor, meaning that it causes the small blood vessels in your hands, feet, and elsewhere to constrict, limiting blood flow. That can increase your risk of conditions like frostbite because warm blood isn’t flowing to those areas. Also, we typically associate dehydration with summertime and sweating, but in cold conditions, this is also a concern because the air is so dry. We're still losing moisture with every breath, plus we may be sweating, and the wicking layers we wear are dissipating that moisture as they’re designed to, and we don’t notice the sweat as we would in the summer. Stay hydrated.

—Jeremy

Shopping list:

Sportown Men's Merino Wool Lightweight Long Sleeve Crew Base Layer Top, XXL 

Minus33 100% Merino Wool Base Layer 706 Midweight Bottoms Black XL

Balaclava Fleece Hood – Windproof Face Ski Mask – Ultimate Thermal Retention & Moisture Wicking with Performance Soft Fleece Construction, Black, One Size

Mad Bomber Supplex Hat with Grey Fur, Black, Medium

RefrigiWear Insulated Wool Gloves Green Large

Fox River Outdoor Wick Dry Alturas Ultra-Lightweight Liner Socks, Medium, White

Wigwam Men's 40 Below Heavyweight Boot Socks, Grey Twist, X-Large

Ski Goggles for Youth Age 8-16 ¨C UV400 Protection and Anti-Fog ¨C Double Grey Spherical Lens for Sunny and Cloudy Days (Black)