Often when I drive in the daytime, it’s cool outside (50° F = 10° C) and all heat is turned off, but there are “pockets of heat” that I feel intently on my face and clothes. Sometimes my ear will feel very hot, or a certain spot on my jeans or jacket. When I touch it it’s really hot to the touch, despite the cool weather.
If I get out of the car or roll my window down, there’s no intense sunlight or heat outside. It’s as if something inside creates stronger heat in some places, or focuses the sun’s rays more strongly.
The car has a white exterior and a dark/charcoal leatherette interior. It does not have tinted windows. But why would tinted windows be necessary in this case when it’s not all that sunny outside in the first place?
Sunlight through glass creates passive solar gain.
I have a glassed in porch, on my south facing house. And I live where we have remarkably cold winters. But on even the coldest days, if it’s cloudless and sunny, by mid afternoon you can comfortably sit out there.
On days when the sun isn’t shining, it remains so cold that snow I’ve tracked in doesn’t melt from my boots!
Greenhouse effect. Energy enters as light, which can pass through the windows. Places where the light hits – i.e. the interior of the car – absorb the light, are heated by it, and then re-radiate energy as heat. The heat cannot pass through the glass the same way light can, so the interior heats up. Sometimes light is hitting one side or even just one spot more intensely, and if that’s on your body, you’ll feel it.
I always find it interesting when I make a turn in the car and the hyperlocal climate changes … despite being in a small, enclosed car cabin. I know why it happens, local pockets like quoted, but it’s still fascinating that inertial applies to air in a fast moving car.
Well, the car engine generates an enormous amount of heat. Part of this is converted to motion, part of it goes out the exhaust, part of it heats air–but part of it is conducted to the car body.
Even when the climate control system is turned off, it may not actually be completely off. No fan, no A/C, but usually the vent dampers are still open to allow fresh air from outside through (there will be more if you’re driving faster) and hot water is still flowing to the heater core. Some automatic climate controls may even attempt to vary the air temperature based on the last thermostat setting by adjusting the air mixing dampers.
So you’re saying even in a closed car, with all windows rolled up, it’s still possible to get tanned, when you feel that pocket of heat on your face? The trucker you linked to in the article doesn’t have a more tanned side of the face, he has a wrinklier side of the face.
Does this also mean that, for example, office workers who work in cubicles facing the sun also get tanned?
I’ve noticed when it’s mildly cool out, like say 60° out, my car is still noticeably warmer when I get inside of it. And this is at night. How does that happen?
Yep. If UV gets through the glass, it can damage the skin. Tanned skin does fade after a bit - think of how pale we are in the spring, when we’ve barely been outside for months - but the damage done by the sun is permanent.
That photo is pretty shocking though - I’ve never seen that big, or obvious, a difference.
I had once read that glass generally blocks UV - but clearly (hah) it doesn’t block enough. Picture-framing shops will offer UV-protectant glass as an upgrade when you’re getting a custom framing job done.
A quick search just now suggests that window glass will block UV-B - but will NOT block UV-A. This article suggests that it’s UV-B that causes a burn but UV-A causes tanning and wrinkles. And the windshield (laminated glass) protects you more than the side window (not laminated).
When the windows have been rolled up all day, it takes hours for the car to cool down back down to ambient temperature. As other people have said, glass traps heat.
You will not get tanned from the “pocket of heat” that’s just hot air. You get tanned from the sunlight going through the glass and impinging on your skin.
One reason is that when you’re outside, the heat from the sun that strikes your body radiates away to the vast space outside. The heat doesn’t accumulate around your body like it does in your enclosed car.