Are You Becoming Cold-Sensitive?
As people get older, they often relocate to places with a warmer climate. In fact, purchasing a retirement home in a sunny location (such as southern Arizona or Florida) to live in during the winter months is fairly common for those who can afford it. This quest for humans to escape cold weather during their retirement years may have a physiological basis according to Robert Yezierski, Ph.D., and his team at the University of Florida, who looked at the sensitivity to heat and cold stimuli as rats age.
Many chronic, painful conditions tend to increase with age, such as rheumatoid arthritis, diabetes, cancer, and fibromyalgia. “Important to understanding these conditions is the question of how advancing age changes the processing and ultimately the perception of pain,” comments Yezierski in his study presented at the May 2008 American Pain Society (APS) meeting.
Rats of varying ages were injected in the hind paws with a substance that causes a temporary state of inflamation and discomfort. Next they were evaluated for changes in thermal sensitivity as a function of advancing age using four different age groups: 8 months, 16 months, 24 months and 32 months. In rat time, 8-10 months of age is considered mature, while 37 months is considered “very old.” The rats were tested to determine their relative degree of thermal preference and the speed at which they escaped cold and hot environments (50 degrees F and 112 degrees F).
Yezierski found that the older the rat, the greater their preference to heat (i.e., aversion to cold), implying an increased cold sensitivity as animals age. He also found that the speed at which the 32-month old rats escaped from the cold and hot environments was faster than for any of the other age groups. In fact, the 8- and 16-month old rats were not bothered by exposure to the hot/cold climates.
Although this study was done in rats, not humans, it lends support to the common phenomena expressed by retirement-aged people who can no longer stand the cold and also tend to develop an aversion to extremely hot climates.