Cold Stress Conditions

2/7/2011

Bbbbbrrrrrr! “But baby it’s COLD outside!” Is that ever an understatement! That line from the famous Christmas song (performed by such greats as Ray Charles, Dean Martin, Elle Fitzgerald and Bart’s sister, Jessica Simpson) was never as true as this past week.  It was COLD – dangerously cold. Temperatures plunged into the negative digits throughout the country. Yes, places like Idaho and Chicago were paralyzed by the extreme temperatures. However people in New Mexico weren’t dressed in Hawaiian shirts and shorts, sunning themselves while drinking pina coladas on lounge chairs either.  Water pipes burst, gas lines were inoperable and the Los Alamos National laboratory shut down for a day.   Just walking from the car to the office was painful.

As with most unpleasant sensations (malodorous chemicals, eye irritants, etc), the pain from cold exposure is a sign that we are in harm’s way and therefore we need to remove ourselves from the environment – the sooner the better. In the case of cold, there are many serious conditions that can result in devastating health effects – including death. During World War I, the American Doughboy learned about Trench Foot: a condition caused by an accumulation of moisture in the trenches, resulting in their feet being perpetually wet. When cold weather hit, soldiers succumbed to foot sores and lesions. Coupled with poor circulation, infections and skin necrosis set in; many times requiring amputation.

In general, cold stress disorders are referred as hypothermia: literally meaning “low-heat.” Hypothermia has been called a silent killer, as many people who succumb to this condition are not aware of the threat. It develops when body heat is lost to a cool or cold environment faster than it can be replaced. Temperatures do not have to be below freezing for hypothermia to occur, especially in vulnerable individuals. Many older adults can develop a low body temperature after exposure to conditions of mild cold, which would only produce discomfort in younger people.

The human defense system will do anything to ensure survival; even at the expense of losing extremities. Because loss of body heat occurs mostly through the hands, feet, and head, it is very important to keep these regions warm with proper clothing (insulated gloves, shoes/boots and hats). When these regions are subjected to cold conditions, the blood vessels leading to these areas will constrict, significantly reducing the amount of blood flowing to these areas. This process results in preventing heat loss as the warm blood that normally flows to these regions will not be allowed to participate in a natural heat exchange sequence due to convention and conduction principles with the cold surroundings. Such automatic responses are controlled through involuntary functions operated by the hypothalamus (situated just above the brain stem).  This means that if we do not properly protect the extremities, without any cognizant judgment on our part, blood circulation to these regions will cease and cellular necrosis (death) may result. Without immediate adjustment, loss of limbs could result. Keep in mind that this event is happening because the body’s defenses are designed to preserve the body by ensuring the torso remains warm by stopping heat loss through the extremities.  

Hypothermia can occur at temperatures around 30̊ F and is easily accelerated as the temperature decreases.  Below is a list of symptoms associated with hypothermia:

• Reduction of body temperature
• Uncontrollable shivering
• Muscle rigidity
• Slow/irregular heart rate
• Low blood pressure
• Exhaustion
• Confusion
• Loss of reasoning
• Pain in extremities
• Severe shivering  
• Severe blood pressure, heart rate, and respiratory reduction
• Death

The last one listed, death, will almost assuredly occur when the body core temperature reaches 78̊ F.

Other conditions brought on by cold stress include frostbite, Raynaud’s Phenomenon, Acrocyanosis and Thromboangiitis Obliterans (Buerger’s Disease). Below is a brief description of these conditions.

Frostbite: More common than hypothermia, frostbite is a result of freezing the extracellular fluid in the skin, which can permanently damage the tissue. It usually occurs in the extremities, such as the tips of the fingers, ears and nose. While there is initial pain, it may subside as the nerves are damaged. The affected area may appear white or grayish.  Because the face is often less protected that other areas of the body, the victim may be unaware of the ensuing condition.   While not considered to be life threatening, the damage caused by frostbite can be physically severe and permanent.

Raynaud’s Phenomenon: Disorder causing discoloration of the fingers, toes, and occasionally other areas. This condition is the result of blood vessel spasms, followed by reduced blood flow to these regions. While Raynaud’s Phenomenon is not a condition that is totally attributed to cold stress, exposure to cold environments has been recognized as one of its triggers.

Acrocyanosis: Decrease in the amount of oxygen delivered to the extremities. The hands and feet turn blue because of the lack of oxygen. Decreased blood supply to the affected areas is caused by constriction or spasm of small blood vessels.

Thromboangiitis Obliterans (Buerger’s Disease): This is an inflammatory condition of the arteries that can be brought on due to exposure to cold weather conditions. Such inflammation may result in blood clots. Results can be stroke, heart attack, and gangrene (requiring amputation). 

These conditions are real and serious.  So dress warmly, wear insulated gloves, socks, shoes and hats, use the buddy system, stay dry, and take breaks in warm sheltered areas.  If you feel the onset of any of these symptoms or notice them in a fellow-worker, stop work, seek shelter, evaluate and if needed, get medical assistance.

For a long time it had seemed to me that life was about to begin–real life. But there was always some obstacle in the way, something to be gotten through first, some unfinished business, time still to be served, a debt to be paid. Then life would begin. At last it dawned on me that these obstacles were my life

Alfred D. Souza