Here’s the thing nobody really thinks about on road trips or long drives: the sun beating through your car window is still doing damage. You’re not protected just because there’s glass between you and the sky.
It comes down to two types of ultraviolet rays — UVB and UVA. UVB is the one that gives you a classic sunburn, the red, painful kind that shows up a few hours later. Glass does block UVB pretty well. So in that one specific way, yes, a car window is doing something useful.
But UVA is a different story. According to University of Utah Health, car windows let UVA radiation through — and UVA is the type linked to skin aging and melanoma, the most dangerous form of skin cancer. It penetrates deeper into your skin than UVB does. And it doesn’t announce itself. You won’t feel the burn the same way. It’s just quietly doing its thing while you’re vibing to a playlist and watching the highway go by.
This is especially relevant for the side windows in most cars. In many modern vehicles, the front windshield tends to have extra UV protection built in due to its laminated glass construction, but your side and rear windows typically don’t have that same level of treatment. So if you’re the passenger sitting right next to the window for a few hours, your left arm and side of your face are taking a real hit.
Prolonged exposure through glass can lead to skin damage, premature aging, and an increased risk of skin cancer — and it doesn’t take a beach vacation for that to add up. Commutes, long rides, sitting by a sunny office or classroom window — it all counts.
The fix is actually simple. Sunscreen on exposed skin before you get in the car. SPF 30 or higher. Focus on your hands, forearms, face, and neck — wherever sun actually hits you through the window. If you’re doing a multi-hour drive regularly, that should honestly just become part of your routine.
Some people also use UV-blocking window film on their car windows. That’s a longer-term solution, but sunscreen is something you can do today, right now, with stuff you probably already have.