Cold Stress
Cold stress occurs when the skin temperatures drops and eventually leads to the internal body temperature dropping as well. This can lead to serious health problems including tissue damage and even death. Two of the main factors that contribute to cold stress are cold weather and wind chill.
Cold Weather – How cold is too cold?
What’s considered “too cold” can vary based on body type, pre-existing health conditions, geographic location, and more. Regardless of what is considered too cold for you, layering FR garments is the best practice for staying warm and compliant this winter. From FR base layers to outerwear, layering FR garments allows you to add or remove warmth to adjust to your working conditions. Given the requirements and physical demands of a job, it’s possible to be cold one minute then sweating the next. Any moisture, even from body sweat, that is trapped on the body can accelerate the rate at which you loss heat.
The FR Control 2.0™ base layers feature moisture wicking technology and actively work to regulate skin temperature (+/- 3 degrees) to keep you warm when it’s cold and comfortable when you’re active. Adding a moisture wicking performance layer on top of the FR Control 2.0 base layer creates a moisture management system that pulls moisture from the skin and pushes it to the outside of the garment, keeping you dry.
Wind Chill – The “feels like” temperature
Sometimes referred to as the “feels like” temperature, wind chill is the quantity expressing the effective lowering of the air temperature caused by the wind. Simply put – as wind speed increases, the "feels like" temperature decreases. Created by the National Weather Service, the Wind Chill Temperature (WCT) index uses advances in science, technology, and computer modeling to provide an accurate, understandable, and useful formula for calculating the dangers from winter winds and freezing temperatures. Although this can be used help gauge the wind chill, local conditions such as time of day and precipitation should be taken into account. A drop in the “feels like” temperature can cause the body to lose more heat than normal, accelerating the effects of cold stress.
Wearing an FR outerwear layer that protects you from the wind, such as our HYDROlite FR™ foul weather gear, minimizes the effect of wind chill.
The combination of cold weather and wind can cause the rapid loss of heat from the body. Fatigue, shivering, lack of coordination, slurred speech, and pale, cold skin are all early symptoms of cold stress and should be monitored for at all times. If symptoms worsen, cold related illnesses can develop such as:
Hypothermia
Occurs when body heat is lost faster than it can be replaced and the body temperature (normally at 98.6oF) drops below 95oF.
Frostbite
An injury, typically affecting the extremities such as hands and feet, caused by the freezing of skin and underlying tissue.
Immersion/trench foot
Caused by prolonged exposure to wet and cold temperatures, this occurs when the body attempts to conserve heat by constricting the blood the blood vessels to shut down circulation to the feet. While layering FR clothing is the best practice for staying warm, it is important to be aware of the early symptoms of cold stress and take action as needed. For more information on cold stress and related illnesses, check out OSHA’s winter weather guide.
Foul Weather – Sleet, Snow, Rain
Keeping the weather out and warmth in is the essential function of foul weather gear. During the winter, your FR foul weather gear must keep you warm and dry all while providing the necessary protection to keep you safe. Whether it be sleet, snow, or rain, any moisture that seeps through your outer layer puts you at a greater risk for developing cold stress related illnesses. Although protecting against cold stress is important, it is equally important to avoid overheating caused by non-breathable FR outerwear. Non breathable outerwear can trap heat and moisture inside, causing discomfort and even heat stress. To stay warm and dry without overheating, it is best to wear waterproof, breathable FR outerwear.
Available in hybrid style, hi-vis yellow and hi-vis orange, the HYDROlite FR foul weather gear is the perfect FR outer layer for keeping winter weather out and warmth in. Made with GORE-TEX PYRAD® technology, the highly breathable, wind and waterproof HYDROlite foul weather gear keeps out winter weather while assisting your performance layers by moving moisture away from the body for greater worker comfort in all weather conditions.
The lightweight fabric dries to the touch quickly, reducing the uncomfortable cold, clammy feeling from reusing damp FR outerwear multiple times during a shift. Whether you’re getting in and out of the truck or need to add/remove warmth, the covered zip front closure with zipper pulls allow you to easily put on or take off the HYDROlite FR hi-vis bomber as needed.
To keep you safe, this foul weather gear offers CAT 3 protection with an arc rating of 31 cal/cm2 and is compliant to ASTM F2733 for Flash Fire.
Low Visibility
FR Hi-vis clothing isn’t just for the summer. In fact, the winter brings a variety of potential hazards that can create even more of a need for FR hi-vis clothing than the summer. Less daylight, foul weather, and the cloudy skies of winter all contribute to decreased visibility for outside workers. This means that many workers need FR hi-vis outerwear that is compliant to ASNI 107 and can keep them warm during the winter.
Layering can be done with FR hi-vis clothing to allow you to add or remove warmth without sacrificing visibility. For warmth without restricted range of motion, the DRIFIRE® Performance FR Hi-Vis Long Sleeve T-Shirt is the perfect mid weight layer. Adding an FR hi-vis sweatshirt on top, like the clean style VIZABLE FR® Hi-Vis Hybrid Lined Zip Front Sweatshirt, provides increased warmth, protection, and ANSI 107 compliance.
Whether you need hi-vis yellow or hi-vis orange will depend on job function, employer requirements, and geographic location. For example, working in wooded areas may require hi-vis orange instead of hi-vis yellow because orange provides greater contrast against the green background.
The best way to avoid potential injury this winter is to select comfortable FR clothing that keeps you warm, dry, and protected. Being aware of all potential hazards, as well as employer and industry standards, is a fundamental part of this process. To find out more about the winter FR clothing options available at NSA, contact our customer service team through email at customerservice@thinknsa.com or by phone at 1-800-553-0672.