Why do we feel uncomfortable at 98F ambient? Shouldn’t that air temp be roughly the same as sticking a hand in lukewarm water - you don’t really “feel” it? I would think that room temp, about 70F, ought to register as nearly thirty degrees too cold.
Your body is constantly producing heat. In order to maintain your body temperature, you need to get rid of the extra heat. The colder it is around you, the faster your body can get rid of extra heat. Of course, if it gets too cold, you lose too much heat and die.
In 98-degree weather, it’s much more difficult for your body to radiate excess heat, because the air around you isn’t any colder than you are. Additionally, in most climates, 98-degree weather is associated with high humidity, which makes sweating less efficient.
Heat transfer. Our bodies can hold 98.6 degrees (give or take) because we can dump excess heat into the environment. The rate at which that happens is partially dependent upon the temperature difference between your body and the surrounding air–the higher the outside temperature, the lower the transfer rate and the harder it is to keep your core temperature down. We feel most comfortable at an ambient temperature at which internal heat production approximately balances heat loss to the environment and for most of us, that happens in the mid to low 70s.
Your body is generating heat itself and needs to get rid of it to keep itself cooled. Temperatures around 70F are a good equilibrium point for that. Temperatures in the 90’s aren’t all that bad unless the humidity is very high. Phoenix may not seem so bad on a 98F day but New Orleans and Houston generally will because the body’s main cooling mechanism is compromised and it has to switch over to secondary cooling like sweat to protect itself. That process is uncomfortable to most people.
Let’s also remember that the issue is complicated by pants.
Specifically, most people are now wearing clothing that traps heat near their body, and hence reduces the rate of heat transfer away from it. As other posters note well, heat transfer means we’d probably feel most comfortable at some temperature less than 98.6. The fact that we’re all clad may help those of us in the frozen northern wastes function, but it also helps trap air close to our bodies, limits the rate at which heat is given off, and hence makes us comfortable at an even lower temperature than we’d be comfortable at otherwise.
The other factor is that water has a much higher thermal conductivity than air. Being immersed in water that is at a temperature that would be balmy or maybe a bit chilly if we were talking about air temperature will lead to death from hypothermia in a matter of hours.
For completeness’ sake, the Master speaketh.
Interesting point I hadn’t really thought of before - what is the ideally comfortable temperature for naked people?
Cecil suggests someone “very lightly dressed may prefer 80”, but IMO, a scientific experiment is definitely in order here.
So if I’m backstage at the Victoria’s Secrets lingerie show and I keep telling the models, “Damn, you’re hot!” just keep in mind I’m a scientist.
I don’t think that clothing would be too much of a complicating factor, though: People out in very hot weather generally wear very little in the way of clothing, and what they do wear is designed for minimal insulation.
To add to all of the other answers, realize that because the body produces heat as a consequence of metabolism, if the body is unable to transfer heat to the environment, the body’s internal temperature will start to rise above 98 deg F.
This is why 98 deg F air feels uncomfortable. If the air is the same temperature as the body, heat is not removed, and body temperature will start to rise*. This is why you start sweating, so that evaporative cooling takes the place of cooling by convection.
*Note that if the body’s temperature rises above that of ambient temperature, some heat will then transfer from the body to the environment. However, if the body’s internal temperature rises too far, heat stroke/heat exhaustion can occur, which can lead to death. Also, excessive sweating can lead to dehydration and salt depletion.
In this, as in so many other aspects of life…
Hence my motto “Pants are superfluous!”
Thank you all!
Okay, I get it. Makes sense. Somehow I missed this in school!
I’ll toss in my $0.02 American. Years ago, I had a job that took me to Antelope Valley in California (next door to the Mojave Desert). Inside the office, the temp was probably 80 degrees and it felt warm. Outside, it could be 115, but my armpits would get chilled. Low humidity is a great thing in warm places, high humidity is a killer.
Also keep in mind that 98.6 is internal temperature. The skin and exposed areas are typically lower - around 91 degrees or so. So any temperature above that will feel hot.