Winter

Wind Chill Temperature: A Guide for Employers

Outdoor workers exposed to cold, wet, windy conditions are at risk for cold stress. Both air temperature and wind speed affect how cold they feel. Remember that not everybody experiences cold conditions the same way. Some people are more sensitive to the cold than others. Their body temperature may be lower than 98.6 degrees to start off with -they are known as “cold-natured”; Others’ body temperature may be more “warm-natured” having a body temperature above 98.6 degrees. Take this into consideration when assigning work outdoors in the winter.

Windchill is the term used to describe the rate of heat loss from the human body, resulting from the combined effect of low air temperature and wind speed. The windchill temperature is a single value that takes both air temperature and wind speed into account. For example, when the air temperature is 40 degrees F, and wind speed is 35 mph, the wind chill temperature is 28 degrees F; This measurement is the actual effect of the environmental cold on exposed skin. Add moisture (rain, snow, high humidity) to the mix and it further increases the risk of cold stress illness.

Remember to watch your local weather forecasts and take measures to protect your employees working outdoors. A little preventive planning can save time, money, and suffering.

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Stay Hydrated in Cold Weather

Losing excessive amounts of body fluid is not usually a hazard associated with cold weather. Most people associate dehydration with summer heat and humidity, but winter can drain the body of essential fluids for several reasons:

  • In winter, people tend to go longer without water, not realizing that breathing cold/dry air causes the body to lose significant amounts of fluid.

  • When we perspire in cold weather, the sweat turns into vapor and isn’t directly on the skin, so there is not the excessive perspiration that acts as a visual cue for us to drink.

  • In winter, people feel approximately 40% less thirsty, even though the body needs the same amount of water all year round.

  • Because we don’t feel thirsty as much as in the summer, we’re less likely to keep water handy in cold-weather months.

Dehydration is a danger to the body any time of the year. Most people don’t realize the hazards it poses to the heart. We need at least six 8-ounce glasses of water each day or we become dehydrated and have less blood volume, the heart must beat faster to keep oxygen and nutrients supplied to other vital organs.

Why is it so important to heart health that the body stay adequately hydrated? Consider these numbers: The body is 70% water. It is essential to health to maintain that level of water to regulate metabolism and stay healthy. For example, if a person weighs 100 pounds, 70 pounds of that weight should be water. If this ratio drops, the heart is deprived of fluid, and has to pump harder to get blood circulating and blood volume decreases. To preserve itself the body directs flow to the body core and organs. As a result, the blood vessels in the extremities (arms, hands, legs, and feet) stiffen up and constrict, putting the person at greater risk of frostbite and hypothermia.

There is a natural loss of fluid during the day from respiration and perspiration. If you are physically active in any way, you need to drink 32 ounces of fluid to maintain a healthy proportion of water in the body. If dressed in warm clothing, you sweat more and require even more fluid intake during the day. The combination of wearing warm clothing and high-intensity activity (exercise) leads to increased sweating and the possibility of dehydration. You may not feel thirsty in cold weather because your body chemistry impairs the brain’s ability to tell you when to hydrate.

One group of people who often become dehydrated is firefighters, because they are working strenuously in heavy layers of clothing. They must make themselves drink fluids even though they don’t feel thirsty.

To avoid dehydration in cold weather:

  • Take fluids with you when you leave the house.

  • If you don’t feel like drinking water, drink warm non-caffeinated drinks like tea, juice, or coffee to help the body stay hydrated.

  • Drink often, even if you are not thirsty.

  • Remember, certain fluids dehydrate the body. These include alcohol and carbonated or caffeinated drinks, including sports and energy drinks - avoid these.

  • Monitor the color and amount of urine your body is producing. Your urine should be light yellow or clear. If it is darker, drink more water.

  • Familiarize yourself with other common symptoms of dehydration including fatigue, feeling lightheaded, and irritability.

Any responsible person that does a lot of heavy manual labor and activity in the winter must keep their body hydrated. You are doing your body a great favor when you are conscious of your body’s need to stay hydrated in winter.

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How to Dress for Cold Weather

On days when the air is cold, the wind is blowing, and the humidity is high or it’s raining, your clothing strategy is key to keeping you from getting a cold stress injury. Here are some tips for how to dress when the temperatures drop.

Layering lets you adjust your body’s temperature by putting on and removing items of clothing and maintaining an even comfort level as conditions or your exertion levels change. To dress for cold weather, you need three layers for maximum warmth and protection.

  • Base layer: Your long underwear needs to keep your skin as dry as possible.

  • Middle layer: Your fleece or puffy jacket needs to preserve as much body heat as possible.

  • Outer layer: Your rain gear needs to protect you from rain and wind.

 Choosing your base/underwear layer

Warm skin starts with dry skin, so long underwear’s job is to wick perspiration away from you. Synthetic fabrics like polyesters are great at both wicking and drying. Wool is a good natural fiber option that holds its insulating abilities even when wet. Avoid cotton fabrics, as they do not retain their insulating abilities when they get wet.

Think about the fit. Wicking cannot occur in places where fabric is not touching skin, so you want a comfortably snug (not tight) fit everywhere.

Thickness or weight: Heavyweight makes sense for sub-freezing temps and low activity levels. Midweight is a good all-around choice. Lightweight is left to milder conditions.

Choosing your middle/insulating layer

This is the layer most people think about in cold conditions, so it’s not surprising that this layer’s job is to retain warmth.  Insulating materials like fleece are a good start. Make sure your jacket is a heavyweight fleece. When you are working outdoors in serious cold weather conditions, then a puffy jacket/coat should come into play. Down coats and jackets are a good standard if you are not working in wet conditions. They lose their insulating ability when they get wet. Puffy jackets/coats with synthetic fills are a better option when conditions get damp.

Insulating thickness can be tricky because you can’t rely on thickness to indicate warmth level when insulation types differ. Temperature ratings on labels are not reliable because there are too many variables (wind, rain, activity level, etc.) You can eyeball 2 jackets with identical insulation specs though and conclude that puffier equals warmer.

Full coverage: Don’t just think about jackets/coats - save some love for the legs. Keep some insulated or fleece pants with you, so your lower half can stay as warm as your top half.

Choosing your outer layer (shell coat and pants)

This is our outer line of defense. Even though it’s often referred to as “rainwear”, this layer’s job is to shield the underneath layers from snow, sleet, rain, and wind. There are 3 important attributes to consider when choosing your outer layer.

  •  Precipitation protection: A wicking base layer can’t keep your skin dry if moisture is soaking you from the outside. In winter you don’t want to sacrifice any warmth to evaporation cooling. Wear a shell that is “waterproof” rather than merely “water resistant”.

  • Breathable protection: Perspiration wicked by your base layer needs a way to escape. Wear a shell that is breathable, or moisture can build up inside it and soak you. You don’t need the most expensive GORE-TEX rainwear – any shell that is designated as “waterproof/breathable” should work fine.

  • Windchill protection: The good news is that any shell that is “waterproof” is also “windproof”.

Shell pants- Cold, wet ankles are no fun, so be sure your boot tops are covered. If your pants don’t cover your ankles, then consider wearing a pair of gaiters.

Keeping Your Head, Hands, and Feet Warm

To prevent extremities from getting cold, cover up everywhere. The warmest options in hats, gloves, and footwear do the same thing as layers elsewhere: wick, insulate, and block rain/wind.

Hats- Wool or synthetic beanies work well, and you can rely on your shell jacket/coat’s hood for rain coverage. Full-on winter hats will have insulation inside the shell material. Make sure your headwear covers your ears. If your face is uncomfortably cold, wear a balaclava.

Gloves- Fleece gloves provide basic warmth. Insulated gloves, especially ones with waterproof/breathable shells are better. Mittens are warmer than gloves, because they share finger warmth.

Boots- with thick non-cotton socks can provide warmth when conditions are merely cold, but not wet or snowy. Waterproof boots are the next step up. Winter boots, in addition to offering traction on snow and ice, will also include insulation.

A Warmer Coat- Think of this as a twist on “cold hands, warm heart”. If your heart is warm and toasty, then it has plenty of warm blood to pump out to the hands and feet. Choose a well-insulated waterproof winter coat.

Chemical Warming Packets- Add warmth by slipping hand and foot warmers inside your gloves and socks. They come in a variety of sizes.

Additional Layering Tips for Cold Weather

Don’t wait to adjust layers: Throw on a shell at the first sign of rain or wind and remove your insulating jacket the minute you start to sweat. Staying warm and dry is easier than warming up or drying out.

Cotton is a no-no in any layer: Set aside your love of cotton flannel (or anything cotton) because it soaks up moisture and takes forever to dry out. That is a recipe for hypothermia.

Layers should play well together: Middle and outer layers need to glide on and off. When they fit too tightly over the layers beneath them, adjustments become cumbersome and you risk constricting circulation. Purchase middle and outer layers that are big enough to provide another layer (that of air) between them. This layer of air stays warm and keeps you warmer.

Taking time to make some smart decisions about your winter clothing will keep your warm and toasty and safer this winter.

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Work-Related Winter Safety Tips

Preventing Slips on Snow and Ice

To prevent slips, trips, and falls, employers should clear walking surfaces of snow and ice, and spread deicer, as quickly as possible after a winter storm. In addition, the following precautions will help reduce the likelihood of injuries:

  • Wear proper footwear when walking on snow or ice is unavoidable because it is especially treacherous. A pair of insulated and water-resistant boots with good rubber treads is a must for walking during or after a winter storm. Keeping a pair of rubber over-shoes with good treads which fit over your street shoes is a good idea during the winter months.

  • Take short steps and walk at a slower pace so you can react quickly to a change in traction when walking on an icy or snow-covered walkway. Test your footing before committing your whole weight in a step. Be mindful of “black ice” (a thin sheet of ice on a surface that may not be visible to the naked eye).

  • Use your door or the roof of your vehicle when getting in and out. Avoid parking on ice if possible.

Winter Driving

Although employers cannot control roadway conditions, they can promote safe driving behavior by ensuring workers: recognize the hazards of winter weather driving, for example, driving on snow/ice covered roads; are properly trained for driving in winter weather conditions, and are licensed (as applicable) for the vehicles they operate. Drive safely during the winter:

  • Slow down, take your time, leave earlier than normal

  • Begin slowing at intersections earlier than normal

  • Avoid stopping or parking on hills or inclines

  • Take corners slower than normal

  • Turn into skids and avoid using the brake

  • Give plenty of space between your vehicle and others and stop where you can completely see the tires of the vehicle in front of you at stop signs/stop lights

Employers should set and enforce driver safety policies. Employers should also implement an effective maintenance program for all vehicles and mechanized equipment that workers are required to operate. Crashes can be avoided. Employers should ensure properly trained workers inspect the following vehicle systems to determine if they are working properly:

  • Brakes: Brakes should provide even and balanced braking. Also check that brake fluid is at the proper level.

  • Cooling System: Ensure a proper mixture of 50/50 antifreeze and water in the cooling system at the proper level.

  • Electrical System: Check the ignition system and make sure that the battery is fully charged and that the connections are clean. Check that the alternator belt is in good condition with proper tension.

  • Engine: Inspect all engine systems.

  • Exhaust System: Check exhaust for leaks and that all clamps and hangers are snug.

  • Tires: Check for proper tread depth and no signs of damage or uneven wear. Check for proper tire inflation.

  • Oil: Check that oil is at the proper level.

  • Visibility Systems: Inspect all exterior lights, defrosters (windshield and rear window), and wipers. Install winter windshield wipers.

An emergency kit with the following items is recommended in vehicles:

  • Cellphone or two-way radio

  • Windshield ice scraper

  • Snowbrush

  • Flashlight with extra batteries

  • Shovel

  • Tow chain

  • Traction aids (bag of sand or cat litter)

  • Emergency flares

  • Jumper cables

  • Snacks

  • Water

  • Roadmaps

  • Blankets, change of clothes

Winter Work Zone Traffic Safety
Workers being struck by vehicles or mobile equipment lead to many work zone fatalities or injuries annually. Drivers may skid or lose control of their vehicles more easily when driving on snow and/or ice-covered roads. It is, therefore, important to properly set up work zones with the traffic controls identified by signs, cones, barrels, and barriers to protect workers. Workers exposed to vehicular traffic should wear the appropriate high visibility vest at all times so that they are visible to motorists. Workers should also remain vigilant regarding their surroundings while working in work zones. Pay attention to what is going on around you and where you are stepping.  Identify potential safety hazards and correct or avoid them.

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