The IceRays field guide
Can you get sun through a car window? What gets through, and which arm
Yes, some of the sun's UV can reach you through a car window. How much depends on which window it is, what the glass is made of, and whether the window is up or down. If you drive a lot, the arm closest to the driver's window gets the most of it. In Australia that is your right arm. In the US and Canada it is your left.
Two kinds of UV, two kinds of glass
UV is the part of sunlight that burns and damages skin. You cannot see it or feel it. Two types reach the ground:
- UVB, the main cause of sunburn.
- UVA, which goes deeper into the skin. Cancer Council says both UVA and UVB are linked to skin cancer.
Cars use two different kinds of glass, and they behave differently. This is from Cancer Council's fact sheet on tinted windows:
| Window | Type of glass | What gets through |
|---|---|---|
| Windscreen | Laminated: a plastic layer between two panes | Blocks UVB, and about 98% of UVA |
| Side and rear windows | Usually tempered (toughened) glass | Blocks UVB, but lets through much more UVA. Estimates run as high as 79%, depending on the glass |
So the windscreen does a good job. The side window next to you is a different story. You may not burn through it, because most UVB is blocked. But UVA still gets through, and on a long drive it adds up.
Cancer Council also notes that UV levels inside a car are generally much lower than outside in full sun. That is good news. It just means "lower", not "none", especially for the arm by the window.
Which arm gets the sun?
It comes down to where you sit.
- In Australia (and New Zealand and the UK), we drive on the left and sit on the right. Your right arm rests closest to the driver's window.
- In the US and Canada, people drive on the right and sit on the left. The left arm is by the window.
Passengers get it too, on whichever side the sun is coming from. And the sun moves. Drive north in the morning in Australia and the sun comes in one side; come home in the afternoon and it is on the other. That is one reason to cover both arms, not just one.
Window down? Then it is full sun
If you like driving with the window down and an elbow out, that arm is then in direct sunlight, with no glass at all. Cancer Council points out that tints and window covers only protect you when the windows are closed. Window down means your arm gets the same UV as if you were standing outside.
Who should take this seriously?
Cancer Council says people who spend long periods in a vehicle should use a mix of sun protection. Think about it if you:
- Drive for work, such as deliveries, trades, sales calls or rideshare.
- Do long country drives or caravan trips.
- Do the school or grandkids run every day.
- Like to drive with the window down.
For a short trip to the shops, it matters much less. It is the hours that add up.
What you can do about it
Cancer Council recommends a combination: a long-sleeved shirt with a collar, sunglasses and SPF 50 or higher sunscreen. That way you are protected in the car and when you get out.
Here are the practical options:
- Arm sleeves. Slip them on before you set off. UPF is a rating for fabric; UPF 50+ means the fabric blocks 98% or more of UV. IceRays fabric was tested by ARPANSA in 2015 (black sample) and rated UPF 50+. See what that test covered (PDF, opens in a new tab).
- Window tint or film. Cancer Council says clear or tinted films can cut UV through tempered glass by over 99%. Tint has to meet your state's rules. Our page on sleeves vs window tint compares the two.
- Sunscreen on your face, neck and the backs of your hands.
- Cover your hands. The backs of your hands sit on top of the wheel in the sun. See hands on the wheel.
Sleeves have one big plus over tint: they come with you. When you stop for fuel, a pie or a walk at the lookout, your arms are still covered.
Safety first
Put sleeves on while you are parked. Do not pull them on, adjust them or reach for anything while you are driving. If something feels uncomfortable, pull over somewhere safe first.
More on driving and sun
- Sun sleeves for driving
- Sun sleeves vs window tint: which does what for drivers
- Hands on the wheel: sun on your hands and arms while driving
- Do arm sleeves protect from sun?
A pair covers both arms. The IceRays 4-pack is AUD 120 for four pairs, or $30 a pair, saving $31.80 on four singles. Keep one pair in the glovebox. In the US, the 4-pack is USD 100. One size fits all adults.
Related guides
- Arm sleeves vs sunscreen: which suits your arms?
- Does sleeve colour matter for sun protection?
- Sun sleeves for walking and everyday outdoor time
- The UV index: a simple guide for Australians
- UV arm sleeves: the complete guide
- Will one size fit me? IceRays sleeve sizing explained
Common questions
Can you get sunburnt through a car window?
It is unlikely, because car glass blocks most UVB, the main cause of sunburn. But side windows can let through a lot of UVA, which also damages skin. You can have skin damage without a burn.
Does the windscreen block UV?
Mostly. Cancer Council says laminated windscreens block UVB and about 98% of UVA. Side and rear windows usually let through much more UVA.
Why is my right arm more tanned than my left?
In Australia the driver sits on the right, so the right arm is closest to the side window and gets the most sun. In the US and Canada it is the left arm.
Do I need sun protection for short drives?
Short trips add little. It is regular long drives, driving for work, and driving with the window down that are worth planning for.
Are sleeves comfortable to drive in?
They are thin and stretchy, so they should not get in the way of steering. Put them on before you start and check you can move freely.