Taking the Heat

The view of my backyard March 11 2018

To complain about the weather is human, so it is no surprise that almost every conversation I’ve had in past few days included complaints about summer heat, which locally ticked up to around 92 degrees (33 C), and about the characteristic NJ humidity. The complaints are not from me. I don’t argue though. I listen politely, but then move on to other topics. As a schoolboy I used to claim that winter was my favorite season. It was a lie. I was just being contrary. Yes, some snow sports are fun, but summer activities are better – and what kid doesn’t like summer vacation? Still, I liked winter well enough back then: it just wasn’t my favorite three months of the year. Nowadays when I have to shovel my own walks, drive myself on icy roads, and pay my own heating bills, I have little affection for winter. I remember what my backyard looked like just a few months ago. I remember what my house was like during a cold week without heat and power when a wind and snow storm took down power lines this past March. Given a choice I’ll opt for too warm over too cold – assuming non-lethal temperatures either way, that is. What of spring and autumn? They have their attractions but they aren’t the opposite of winter. As a favorite quarter-year, at least in this locale, it’s summertime for me.

The view out back this morning

According to a Gallup poll, only 11% of the U.S. population say winter is their favorite season. Summer is chosen by 25%, autumn by 27%, and spring by 36%. In a way it is surprising that summer gets no more than a one-quarter share. Humans are, after all, tropical creatures fine-tuned for the savanna. According to the very untropical Professor Hannu Rintamäki of the Finnish Institute of Occupational Health, unclothed people, when at rest on land, are most comfortable with an air temperature of 27 C (80 F); to be comfortable in water, people require a water temperature of 33 C (92 F). I can attest anecdotally to the air/water difference. I rarely heat my pool, and guests complain (a lot) about the cold when the water temperature is 80 F (27 C). (They also usually disbelieve the temperature reading and insist it can't be more than 60 [16].) In truth 80 degree water is cold enough for hypothermia to set in. (Scientific American: “Even water temperatures as high as 75 and 80 degrees F [24 and 27 degrees C] can be dangerous, but it would most likely take much longer than 15 minutes to become debilitated.”) For a person unclothed in open air with no wind chill, one hour at -1 C (30 F) is enough for lethal hypothermia.

The comfort zone of temperatures depends on activity, of course. The greater the exertion, the more heat we generate, and the cooler we like our environment to be so we can shed that excess heat. Professor Rintamäki mentions that people feel discomfort when their skin temperatures rise above 35 C or fall below 31 C. We feel best with core temperatures between 36.5 and 37.1. Hard though they may be on our clothes, our sweat glands are a great help in regulating body heat. Humans have far more sweat glands per unit of surface area than any other primate.

Speaking of clothes, they are the most likely explanation for why most people set their home thermostats well below 80 degrees (27 C) and favor seasons other than summer. Even the lightest fabric reduces heat loss substantially – in effect creating a tropical microclimate at the skin surface. We crank up the air conditioning to compensate. We have a pretty good estimate of when people started to wear clothes. DNA analysis shows that human body lice diverged from head lice some 107,000 years ago. Body lice don’t really attach to the body; unlike other lice, their claws are adapted to inhabit clothes. So, clothes have been around for at least 107,000 years. They were a key technology for permitting the spread of modern humans out of Africa and into cooler regions starting some 60,000 years ago.

Clothes aren’t going away anytime soon. On the whole, I’m happy with that on purely aesthetic grounds. It is the rare person who looks better out of clothes than in them. Those that do actually can make a living displaying themselves. (That’s never really been an option for me.) So, I suppose it is understandable that 75% of our garmented public prefer seasons at least somewhat cooler than summer; it is likely I will remain in a minority for the foreseeable future. That’s OK: the coming and going of the seasons are not subject to majority vote. Until the next equinox (September 22 this year) I’m in my preferred element. If the mercury climbs enough to tempt me to gripe, a peek at my photos from last winter will be enough to restore my equanimity.

Janis Joplin – Summertime