Hot and Cold

Waking to a 23 degree morning, our third “episode” of below freezing weather this winter, I wondered, as I have over the past several years, how Mike and I are going to “grow old” and stay warm in this drafty, thin-walled, old-glass windowed house. I also wonder why the cold bothers both of us more than earlier in our lives. What I don’t wonder is why people become “snow birds”, heading to warmer climes in the winter!

The flip side is a matching decreased tolerance for heat. Recently, I’ve become even more interested in this heat and cold mystery of our biology having learned too much heat, raising the body’s core temperature, is one cause of lymphedema, a condition many people get who have mastectomy with lymph node dissection surgery, as I did a month ago. When ask doctors and lymphedema specialists why this is so, no one knows for sure the biomechanics of the cause and effect process.

Mom became sensitive to temperatures in the last decade of her life, where previously she was pretty hardy in both hot humid weather and cold wintry weather. It was as though her internal thermostat no longer worked, which is how I often describe my own thermal sensitivities. Certain health conditions can cause intolerance for heat and cold outside a narrow range (a factor with me), as do certain medications (unfortunately a factor for Mike). But clearly, aging is a general factor for many people.

In a brief exploration of thermal sensitivity, I find not a lot is known why it changes as we age.  Aging blood vessels lose some flexibility and do not dilate as readily, thus not adapting to changes in external temperatures.  In his book The Clock of Ages: Why We age, How We Age, Winding Back the Clock, Dr. John Medina, an Associate Professor of Bioengeering at University of Washington Medical School writes:

“Measurements of thermal sensitivity are complicated by our perceptions. Specifically, we have a curious psychological ability to adapt to temperature differences. This adaptability plays such a large role in our perceptions that what we experience as cold in one season may be hot in another.”

He goes on to say

“Is there anything we can say about aging and thermal sensitivity? There is some research indicating that higher thresholds of heat are needed before older adults can experience warmth, but until the biology of human thermal sensitivity is better understood, the data regarding age-related changes in detecting hot and cold are mostly commentary.”

It seems though we know the outcome of these thermal sensitivity changes, and certainly elderly people are more prone to hypothermia and heat stroke and need to be looked after and cared for (Mike and I are open to the ‘elderly being cared for part’!), it is a mystery as to the why.

frost flowers

Walking Abby today, I saw something I don’t recall seeing before. I wasn’t sure if it was fungus or ice. It looked like 3″ high fluffy, cotton candy snow, though there was no snow anywhere around. Gently touching it, it felt silky and fine, not at all icy. A quick internet search and I learned about “frost flowers” which form only on dead wood, a result of certain chemical changes in the decaying process when the temperature drops below freezing. Even wood, as it decays, responds to cold weather differently (and quite creatively) than green wood. I’m not implying Mike and I, or our age peers, are decaying, though all living beings are, in a sense, as we grow older!

So where is the connection and why am I sharing all this, which though fascinating to me may be boring to others?  Well, if an rotting stick creates such fastinating beauty when the temperatures drops so low, I too need to focus on the positives…the clear blue skies, clean air, the invigoration I feel as Abby and I walk briskly in the woods.  Back inside, I throw another log in the stove, the warmth center of our home.  Low winter sunlight fills the house, our maple and cherry wood cabinets glow.  Our home is filled with wood…cedar walls, pine walls, oak floors, a velvety smooth maple table that sits next to the kitchen window is golden in the sunlight.  Wood, whether being burned in the stove or reflecting the sunlight, creates a warm, comforting shelter from the cold, a “wooden womb” of sorts, as Abby and I snuggle up.  This may indeed be a home we can grow old in.

Thermal sensitivity, in people and wood, seems a pleasant, mysterious, and seasonally appropriate topic as temperatures dip into the teens tonight.

Happy New Year, stay warm, and take care of elderly folks or your elderly selves!


Post notes on Frost Flowers:  Friends also saw Ice Flowers today on their walk, in their woods. I’m even more curious as to what the specifc conditions were for these to form today.

Links on Frost Flowers:

Snow (fascinating page on types of ice crystals from Caltech)

Ice Stories from 19th and early 20th Centuries

When I Went Into the Woods Today (great photos of ice flowers)


NY Times article on getting older and being colder!

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