Cold weather and alcohol don't mix.

The longstanding notion that alcohol protects from overexposure to cold weather is a myth. "Alcohol in the human body does not act as an anti-freeze when the mercury and wind chill drop to frigid temperatures," explains Landgrave T. Smith, assistant professor of psychiatry and behavioral sciences, university of Oklahoma Health Sciences Center.

"Although alcohol has some caloric value, it is actually a detriment to a person in cold weather. Physiologically, alcohol creates peripheral vessel dilation which results in the rapid loss of body heat." If a person becomes cold, peripheral circulation clamps down to reduce heat loss. Alcohol inhibits this protective response, increasing the risk of exposure.

Individuals who become seriously chilled should warm up gradually. Sudden exposure to heat can produce rapid dilation of the peripheral vessels, and blood pressure will fall. Alcohol may enhance a sudden vascular dilation of this type and increase the severity of the blood pressure drop.

If the blood pressure drop is sudden and severe enough, there will not be enough blood returning to the heart to give it anything to pump. If the heart is deprived, little or no...