Staying a Step Ahead of Cold Feet Trouble

Welcome to Health and Safety to Go, a production of the Canadian Centre for Occupational Health and Safety.

Every day we expose our feet to potential physical injury. Foot problems can occur in almost any workplace and under a wide variety of working conditions, especially in Canada, where the winter introduces unique hazards. While Canadian Standards Association approved safety footwear provides protection from workplace hazards such as crushes, burns and punctures, during the colder months there are cold weather afflictions that can also have painful and sometimes serious consequences.

There are many ways exposure to the cold can affect our health. During the winter, working at outdoor jobs such as logging, hydro line work or fishing can mean working in freezing temperatures, or in low temperature wet conditions, which can put feet at risk of frostbite, chilblains, and trench foot.

Frostbite is caused by freezing of the skin and underlying tissues. First your skin becomes very cold and red, then numb, hard and pale. Frostbite is most common on the fingers, toes, nose, ears, cheeks and chin.

Symptoms include: reduced blood flow to hands and feet, numbness or a loss of feeling, tingling or stinging, aching, and bluish or pale, waxy skin. Frostbite can permanently damage body tissues, and severe cases can lead to amputation.

Let’s talk about chilblains for a moment! Repeated exposure to cold, but not freezing, air can result in chilblains, the painful inflammation of small blood vessels in your skin. Chilblains can cause itching, red patches, swelling, and blistering on your feet and hands.

Chilblains usually clear up within one to three weeks, especially if the weather gets warmer or exposure stops. Chilblains don't usually result in permanent injury. But the condition can lead to infection, which may cause severe damage if left untreated.

Trench foot is an injury of the feet resulting from prolonged exposure to wet and cold conditions. Trench foot can occur at temperatures as high as 15 degrees Celsius if the feet are constantly wet. Injury occurs because wet feet lose heat 25 times faster than dry feet. Therefore, to prevent heat loss, the body constricts blood vessels to shut down circulation in the feet. Skin tissue begins to die because of lack of oxygen and nutrients, and due to the buildup of toxins.

Symptoms of trench foot include: reddening of the skin, numbness, leg cramps, swelling, tingling pain, blisters or ulcers, bleeding under the skin, and gangrene (the foot may turn dark purple, blue, or gray).

Wearing appropriate footwear and socks is an important step in protecting the feet from cold.

“Normal” protective footwear is not designed for cold weather while “insulated” footwear may give little temperature protection in the sole, where there is no insulation.  Loss of heat through steel toe caps (commonly blamed for increased heat loss) is insignificant.

Insulating the legs by wearing thermal undergarments, wearing insulating overshoes over work footwear, and wearing insulating muffs around the ankles and over the top of the footwear can help provide foot protection against cold weather.

Felt-lined, rubber bottomed, leather-topped boots with removable felt insoles are best suited for heavy work in cold since leather is porous, allowing the boots to breathe and perspiration to evaporate. Leather boots can be waterproofed with products that do not block the pores in the leather.

For work that involves standing in water or slush, waterproof boots must be worn. However, while these boots protect the feet from getting wet from cold water, they also prevent perspiration from escaping. The insulating materials and socks will become wet more quickly than when wearing leather boots, and increase the risk for frostbite.

You may prefer to wear one pair of thick, bulky socks or two pairs - one inner sock of silk, nylon, or thin wool and a slightly larger, thick outer sock. Liner socks made from polypropylene will help keep feet dry and warmer by wicking sweat away from the skin. However, as the outer sock becomes damper, its insulation properties decrease. If work conditions permit, have extra socks available so you can dry your feet and change socks during the day. If two pairs of socks are worn, the outer sock should be a larger size so that the inner sock is not compressed.

Always wear the right thickness of socks for your boots. If they are too thick, the boots will be tight, and the socks will lose much of their insulating properties when they are compressed inside the boot. The foot could also be squeezed which will slow the blood flow to the feet, and increase the risk for cold injuries. If the socks are too thin, the boots will fit loosely and may lead to blisters.

For more information and tips on how to keep yourself warm and dry while working in the cold, visit ccohs.ca.Thanks for listening everyone!