Cold Stress Safety | Risks and Solutions

Cold stress – it’s a deadly serious enemy of outdoor cold-weather workers. It’s also stealthy, sneaking up on you to cause injury or even death before you even know something is wrong. Those working outdoors in winter weather or working in cold environments for extended periods are most at risk, but the effects of cold stress can take anyone down.

When should your cold stress red flags pop up? Which of your crew members are most at risk? And what are the most effective steps you can take to keep everyone safe? These are some of the questions that will be examined in this article.

How Cold is Too Cold?

Whenever temperatures drop below normal and wind speed increases, workers are at increased risk for cold stress. Wind chill and wetness boost risk, but surprisingly, cold stress can happen in temperatures as high as 60°F.

Cold stress risk factors include:

• Wetness/dampness, dressing improperly and exhaustion

• Predisposing health conditions such as hypertension, hypothyroidism and diabetes

• Poor physical conditioning

The Mechanics of Cold Stress

The body reacts to cold stress in a logical, systematic manner. As conditions worsen, the body shifts into survival mode by redirecting warmth and blood flow to blood vessels in the most critical area – the body’s core. Extremities like the hands and feet are the first affected areas. Eventually, the body lowers all skin temperature and internal body temperature.

Common conditions caused by cold stress include:

• Hypothermia: As body heat is lost, the body can no longer sustain it’s internal temperature. In order of increasing severity, symptoms start with shivering (which ends when exposure continues), slurred speech, loss of coordination, confusion, disorientation, inability to walk or stand, dilated pupils, slowed pulse and breathing, loss of consciousness and death.

• Trench Foot: Reduced circulation and skin death in the foot, caused by prolonged exposure to wet and cold temperatures. Symptoms include redness of the skin, swelling, numbness, blisters.

• Frostbite: Freezing of the skin and underlying tissues. Frostbite typically affects the extremities, particularly the feet and hands. Symptoms include reddened skin with gray/white patches, numbness, affected skin feels firm or hard, and skin blisters. 

Shorter Shifts, Increased Productivity

Limiting exposure is key in the prevention of cold stress. The dangers only get worse as temperatures lower and the wind speed picks up. Planning for shorter shifts can include adjusting work schedules or rotations to the cold weather or plummeting temps. Scheduling shifts in the middle of the day allows you to take advantage of the solar heat load that accumulates on sunny days.

Cold Weather Work/Rest Schedule

A work/break schedule based on air temperature and wind speed is a smart tool for determining the number and length of work breaks needed during a shift.

Hydrate Even If You’re Not Thirsty

Dehydration is as common in winter months as it is during the summer. Cold weather tends to move body fluids from your extremities to your core, increasing your urine output and adding to dehydration. Just because you’re not sweating as much as you would in the blazing heat of July doesn’t mean you’re not losing moisture. In fact, you can literally see it leaving your body when temps hit freezing and your breath becomes visible.

The Big Chill

There are two sets of factors that come into play when considering the causes of cold stress. The first is personal factors like exhaustion, physical conditioning, healthy circulation and pre-existing conditions like hypertension, hypothyroidism and diabetes.

The second set includes environmental factors, such as cold air temperatures, wind speed, dampness of the air and contact with cold surfaces (hence the importance of thermal work gloves, hats, balaclavas and jackets). When it’s cold, the body must work harder to maintain its temperature. Cold ambient air temperature, water and snow all draw heat from the body. High wind speeds and dampness work to accelerate heat loss.

Calculate Your Risk

When working outside, it’s important to be mindful of how conditions may impact you. Use the NWS (National Weather Service) Windchill Temperature (WCT) index to calculate the dangers from winter winds and freezing temperatures. For example, when the air temperature is 40°F, and the wind speed is 35 mph, your exposed skin receives conditions equivalent to the air temperature being 28°F.

What's Your Plan?

Every employer with an outdoor cold-weather work environment should have a cold stress prevention plan.

·         Supervisors should know the signs and symptoms of cold-related illnesses, as well as the proper response to cold stress

·         Remind all workers of cold stress risks and signs during daily or weekly safety briefings

·         Provide comprehensive cold stress training and a break area for workers with heaters and windbreaks

·         Enclose the work area when possible

·         Encourage your crews to wear insulated, waterproof footwear and keep a dry change of clothing nearby

Communication – The Ultimate Protection

Take a few minutes before a shift to educate your crew on how to work smarter in cold temps. The workwear experts at Ergodyne® have created a guide for cold temperature toolbox talks.

Remember, it doesn’t take extremely cold temps to cause cold stress. Putting worker safety first is paramount when cold temperatures are present. Understandably, workers may slow down in cold weather. But that doesn’t mean productivity has to completely freeze. 

A little planning, forethought and worker communication can go a long way towards keeping your crews healthy, productive and on task.