Hypothermia

Bundling up and dressing in layers can help protect people from cold weather. But sometimes that's not enough. Some people are more vulnerable to temperature changes. In such people, body temperature can drop dramatically, a condition called hypothermia.

The American College of Emergency Physicians (ACEP) says that some of the signs of hypothermia include:

• confusion or sleepiness
• excessive shivering
• weak pulse
• changes in speech or behavior or reactions

Who's most at risk

Age is one of the things that can put you more at risk of developing hypothermia. According to the National Institute on Aging, older people are at risk, not only in very cold weather, but even in mildly cooler temperatures. Seniors on a fixed income may be even more vulnerable if they're unable to afford sufficient heat during the colder months.

In addition to age, certain illness can also make someone more susceptible to the cold. These include:

• thyroid disorders (Read about "Thyroid")
• stroke or any condition that causes paralysis (Read about "Stroke")
• arthritis (Read about "Arthritis and Rheumatic Diseases")
• any conditions that restrict activity or movement
• any conditions that affect blood flow (Read about "Raynaud's Phenomenon")
• memory disorders (Read about "Dementia" "Alzheimer's Disease")

Alcohol also lowers the body's ability to retain heat. (Read about "Alcoholism") In addition, medications can increase temperature sensitivity. If you're taking medications for anxiety or depression, for example, a doctor can provide information on how they'll affect your ability to cope with temperature drops. (Read about "Taking Medicine")

Awareness of the risks

Awareness of the risks of hypothermia can help prevent its occurrence. Older people and their families should be especially aware of the dangers and work with healthcare professionals to reduce the risks.

People who work outdoors in cold weather are also in danger according to the Occupational Safety and Health Administration (OSHA). If you must be outdoors in the cold, OSHA suggests at least three layers of clothing. Also, remember that up to 40 percent of body heat is lost when the head is exposed, so wearing a hat can be a very good idea.

The Centers for Disease Control and Prevention (CDC) advise that adults and children should wear:

• a hat
• a scarf or knit mask to cover face and mouth
• sleeves that are snug at the wrist
• mittens (they are warmer than gloves)
• water-resistant coat and boots
• several layers of loose-fitting clothing

Be sure the outer layer of your clothing is tightly woven, preferably wind resistant, to reduce body-heat loss caused by wind. Next to your skin, you want a fabric that will wick the perspiration (Read about "Sweating") away from your body. Newer, synthetic fabrics are designed to accomplish this effectively. Cotton is not a good choice for the inner layer. CDC says wool, silk or polypropylene inner layers of clothing are a better choice. Staying dry is important; wet clothing chills the body rapidly. Excess perspiration will increase heat loss, so remove extra layers of clothing whenever you feel too warm. Also, avoid getting gasoline or alcohol on your skin while de-icing and fueling your car or using a snow blower. These materials in contact with the skin greatly increase heat loss from the body. Do not ignore shivering. It's an important first sign that the body is losing heat. Persistent shivering is a signal to return indoors.

If you come across someone who has hypothermia, there are things you can do to help. ACEP says for mild hypothermia cases or more severe cases where medical treatment will be significantly delayed, external rewarming techniques may be applied if this can be done safely. This includes body-to-body contact (e.g., placing the person in a prewarmed sleeping bag with a person of normal body temperature), chemical heat packs or insulated hot water bottles. If you use artificial heat sources, make sure they are not so hot that they could burn the skin. Good areas to place these packs can include the armpits, neck, chest and groin. ACEP says it is best to have the person lying down when applying external rewarming. You also may give mildly hypothermic people warm fluids orally, according to ACEP, but avoid beverages containing alcohol or caffeine.