Yes, I have a request: don't turn up the heat too high; seventy degrees would be fine!

In the dead of winter inside a hall with many persons—all their bodies dissipating heat, there’s often no need for HVAC heating. In fact, in this situation, with a well insulated structure, and the thermostat set to 70 degrees F, and the outside temperature not extremely cold, a correctly functioning HVAC-system, would transfer heat from the room, or more specifically, from the occupants’ body-heat, to the outside

Curiously, in recent years, I’ve noticed a desire by many for a warmer ambient temperature. Seventy degrees used to be normal for we descendants of Europe. Seventy is still my preference!

Folks seem to be producing less and less of their own heat. Are humans turning cold-blooded, like reptiles? A reptile doesn’t produce its own heat and has to bask in the sun to absorb warmth.

It’s easy in this modern-age to avail ourselves of heat aplenty. Like our bodies, the internal-combustion car engine must dissipate heat. While driving, this incidental heat provides free-of-cost heating of the car’s interior. This and relatively cheap home and workplace heat promotes intolerance of any unheated areas or drafts. So, we’re becoming accustomed to, and thus requiring more and more heat. A calorie is a unit of heat, and normally we humans burn about 70 percent of our caloric intake to make our necessary body-warmth. I figure that the normal figure of 70% might be declining as persons increasingly rely upon external (environmental) heat sources such as the interior heating of their homes and automobiles. This reliance upon elevated levels of external heat reduces metabolism, thus a reduction of calorie burning. Simply put: the warmer one remains, the fewer calories one needs.

Sedentary employment further slows the metabolic rate thereby adding to the effect of an increased dependency on elevated environmental heat. An acquaintance gave me her opinion on the matter: "They’re at their job all day in their cubicles without much physical activity. Then, wherever they go, they’re cold, and demand more heat as their metabolisms are shot!" I agreed completely; there are many lethargic, physically unfit persons today. No wonder we have a national obesity problem!

Considering the adaptation process of human evolution, I think that continuation of this over-indulgence of extraordinary ambient heat, as well as tolerance of, by those who still require only normal ambient temperature, will eventually cause humans to become cold-blooded. From the relatively modern use of clothing, genetic evolution has done away with most of our hair. Maybe we humans were also extra-indulgent in dressing for warmth way back when we started wearing clothes.

Richard Stuart Otto, 17 Jan 2008