Some of the more common risks to exercising in the cold include frostbite and hypothermia. Public awareness of the danger of these conditions has led to readily available information on the precautionary measures to take in order to prevent their occurrence during cold weather exercise. Another, less well-known complication to exercising in cold environments, but one that can pose a serious health threat to those who are susceptible, is cold urticaria.

Cold urticaria, also called "cold hives," is an allergy to cold temperatures. It is characterized by the development of red, itchy wheals (welts) on the skin with cold exposure. The areas of the skin directly exposed to the cold are the most severely effected. Often, symptoms become worse when the exposed skin is re-warmed.

Triggers include cold weather (typically ambient temperatures below 40 degrees Fahrenheit), cold food and drinks, and aquatic activities in cold water. Wet and windy conditions increase the risk of developing cold urticaria. Although the symptoms of cold urticaria are typically mild, some individuals can experience life-threatening anaphylaxis, particularly with full body exposure (e.g., swimming in cold water). This type of systemic (whole body) reaction can cause rapid heart rate, the "chills," swelling of the extremities and torso, fainting, shock, and even death.

Who is at risk for developing cold urticaria?

• Children and young adults, although it can occur at any age.
• Genetic predisposition - family member who has/had the condition.
• Recent viral infection (e.g., mononucleosis or pneumonia).
• Autoimmune disorders, such as rheumatoid arthritis.

Cause

• Over-response of immune system to cold exposure that results in the release of large amounts of histamine.

Treatment

• Taking antihistamine medication prior to exercising in the cold.
• Prevention - avoiding exercise in cold environments, especially aquatic activities in cold water.

You should see your doctor if you experience any of the above symptoms after exercising out in the cold. Severe symptoms need immediate medical attention. If you have cold urticaria, follow your physicians recommendations for cold weather exercise. He or she may suggest that you move your routine indoors. Other precautionary measures to consider are:

• Wear a medical alert bracelet.
• Carry an injectable epinephrine.
• Exercise with a partner.

Note: Before beginning an exercise program or increasing the intensity level of a current routine, a physician's approval should be obtained, especially for older adults and those at risk for or who currently have chronic health conditions.

Resources:

"Cold Urticaria," Mayo Clinic Staff

ACSM's Resource Manual for Guidelines for Exercise Testing and Prescription, 1993, 2nd edition