In this time-lapse video, we will see infrared
footage of a person’s hand that has just been removed from a bucket of ice water. The hand is dark, depicting cooler temperature,
but watch as white patches start to form. These are areas of inflammation, a sign that
the person is allergic to cold, a condition known as cold urticaria. Inflammation is caused when immune cells release
histamine into the bloodstream. In people with cold urticaria, inflammation produces
hives that are red, itchy, and warm. After 10 minutes, the hand has warmed to about
95 degrees Fahrenheit. The hand will have an elevated temperature for another 30 minutes.
Watch as the person’s fingers begin to swell. In some people, taking an antihistamine can
diminish this inflammatory response. Researchers at the National Institute of Allergy and Infectious
Diseases study cold urticaria and other allergic conditions to better understand, prevent,
and treat them.