HOW COLD IS TOO COLD?
Hypothermia is one of the serious conditions farmers and ranchers may encounter when working in cold temperatures. Recognizing its symptoms and how to respond can help save lives.
A combination of these four environmental factors can easily lead to weather conditions conducive to hypothermia:
* Low temperature
* Strong and/or cold winds
* Cold water
Aaron Yoder, Environmental, Associate Professor for Agricultural and Occupational Health at the University of Nebraska Medical Center, says wind chill is the most dangerous element of winter weather.
“Wind chill is the measure of the rate at which skin exposed to the combined effects of wind and cold loses heat,” Yoder says. “When wind increases, the body loses heat at a faster rate, causing body temperature to decrease.”
Body heat is generated through muscular activity. That heat is lost through the movement of air or water molecules across the skin, through physical contact with another body or object, the process of heat moving away from unprotected surfaces of the body (radiation), and sweating. Generally, the processes of generating and losing heat are balanced so constant body temperature is maintained.
“If a person’s body is unable to produce heat and has either used all its stored energy or is losing body heat faster than it can be produced, body temperature will decrease,” Yoder says. “Once that temperature goes below 95 degrees (Fahrenheit), hypothermia occurs.”
The most common reasons a person loses body heat faster than they can generate it are exposure to cold weather and immersion in cold water.
Shivering, the body’s automatic defense against cold temperature and an attempt to warm itself, is generally the first symptom of hypothermia. If body temperature continues to decline, additional symptoms include:
· Slurred speech or mumbling
· Slow, shallow breathing
· Weak pulse
· Clumsiness or lack of coordination
· Drowsiness or very low energy
· Confusion or memory loss
· Loss of consciousness
· Bright red, cold skin (in infants)
“Hypothermia symptoms begin gradually,” Yoder says. “The affected person isn’t likely to recognize the condition because it happens gradually. Since confused thinking is part of hypothermia, self-awareness is reduced.”
Because the heart and other organs don’t function properly in a hypothermic state, jarring movements may trigger irregular heartbeats in hypothermia victims. If hypothermic conditions are suspected, the victim should gently be moved to a warm area (ideally, inside). If clothing is wet, it should be carefully removed and replaced with warm, dry clothing and/or blankets.
“Prolonged exposure to any environment colder than your body can lead to hypothermia if you aren’t dressed appropriately or can’t control weather conditions,” Yoder says.
To avoid hypothermia, anyone working outside should:
· Wear clothing that’s warm enough for weather conditions
· Avoid staying in the cold too long
· Move to a warm dry location immediately if clothing becomes wet
· Avoid occupying a house with inadequate heat sources
Risk factors that increase potential for hypothermia include advanced or very young age, mental health issues, alcohol and drug use, certain medical conditions and medications.
“As we age, our bodies ability to regulate temperature may lessen,” Yoder says. “Some older adults may lose both the ability to communicate when they are cold and move to a warm location when they feel cold.”
Children lose heat faster than adults do. They are also prone to ignore the cold because they are enjoying being outside or not aware of how cold their body is.
“Children generally don’t have the judgment necessary to dressing properly in cold weather and know they need to move to a warmer location if they feel cold,” Yoder says.
To help keep children from becoming hypothermic, they can be dressed in one more layer of clothing than adults would wear under the same weather conditions. If a child begins to shiver, they should immediately be taken to a warmer location. Have them come inside frequently to warm up and don’t allow babies to sleep in a cold room.
When mental illness, dementia or other factors interfere with a person’s judgment, they may not dress appropriately for weather conditions or fully understand the risk of being outside in cold conditions. If someone with dementia wanders away from home or is susceptible to becoming lost, they are at risk for becoming stranded outside in cold or wet weather.
While alcohol may make a person feel warm internally, alcohol cause blood vessels to expand, speeding heat loss from the surface of the skin. Alcohol also diminishes the body’s ability to shiver, interferes with decisions regarding the need for warm clothing and the ability to determine whether or not there’s a need to seek shelter.
“If a person is intoxicated and passes out in cold weather, it’s likely that they will develop hypothermia,” Yoder says.
Medical conditions such as underactive thyroid, poor nutrition, anorexia nervosa, diabetes, stroke, severe arthritis, Parkinson’s disease, trauma and spinal cord injuries can affect a body’s ability to regulate body temperature. Some drugs can also impact the body’s temperature regulation abilities. Those drugs include antidepressants, antipsychotics, narcotic pain medications and sedatives.
An acronym to help protect yourself from development of hypothermia is: COLD.
C – COVER – Wear a hat or other protective covering to prevent heat escaping from your head, face and neck. Mittens (rather than gloves) are the ideal covering for hands.
O – OVEREXERTION – Avoid activities that cause you to sweat a lot. The combination of wet clothing and cold temperatures can accelerate heat loss.
L – LAYERS – Wear loose fitting, layered, lightweight clothing. Outer clothing made of tightly woven, water-repellant material provides the best protection from wind. Wool, silk or polypropylene inner layers are preferable to cotton for holding body heat.
D – DRY – Stay as dry as possible. If clothing becomes wet, get out of it as soon as possible. It’s easy for snow to get inside mittens and boots, making it especially important to keep hands and feet dry.
Anyone who develops hypothermia due to exposure to cold weather is also vulnerable to freezing of body tissues (frostbite) and decay and death of tissue resulting from an interruption of blood flow (gangrene).
After prolonged exposure to cold, a person may exhibit dilated pupils, decreased pulse, shallow breathing and/or loss of consciousness. In the event of these symptoms, emergency personnel (911) should be summoned. As soon as possible, move the victim to a warm room or shelter (i.e. a vehicle) and remove wet clothing. If available, provide a warm (nonalcoholic or caffeine-free) beverage for them. Keep them dry and warm by wrapping them in a blanket. If no pulse is found, cardio-pulmonary resuscitation (CRR) should be implemented.