Originally published June 2018. Reviewed and corrected August 2026.
Summer in the Ozarks is hot, and the sunscreen aisle is overwhelming. Here is how to choose one and use it properly.
Which SPF?
SPF 30 or higher, broad-spectrum, water-resistant. That covers most people. If you burn easily, have very fair skin, or have a personal or family history of skin cancer, SPF 50 is a reasonable step up.
Above SPF 50 the added benefit becomes very small — the difference between SPF 50 and SPF 100 is a couple of percentage points of UV blocked, not double the protection. Don’t pay a premium for a bigger number.
“Broad-spectrum” matters as much as the SPF. SPF only describes UVB protection — the burning rays. Broad-spectrum means it also covers UVA, which drives aging and contributes to skin cancer without ever making you red.
An important correction
An earlier version of this article said you could multiply the SPF by 10 to work out how many minutes of protection you get — SPF 30 meaning 300 minutes, and so on. That is wrong, and we want to correct it plainly.
The FDA addresses this myth directly: SPF is not a measure of time, it is a measure of the amount of solar exposure. How fast you burn depends on the time of day, the season, altitude, cloud cover, reflection off water or sand, and your own skin — none of which a number on a bottle can know. Someone at the lake at noon in July burns far faster than the same person walking the dog at 6 p.m. in October, wearing the identical sunscreen.
The rule that matters is much simpler:
How to apply it
- Use more than you think. About a shot glass full for your body, and roughly a nickel-sized amount for your face. Most people apply less than half what testing assumes — which quietly turns your SPF 30 into something much lower.
- Apply about 15 minutes before going out.
- Reapply every 2 hours — and immediately after swimming, sweating, or towelling off. “Water resistant” means 40 or 80 minutes in water, not all day.
- Don’t skip the spots everyone forgets: ears, nose, lips (use an SPF lip balm), the back of the neck, hands, tops of the feet, and your hairline or any thinning scalp.
- Never spray directly onto the face. Spray into your hands and apply.
- Check the date. Sunscreen expires; if there’s no date on it, replace it after about three years.
Every day, not just at the pool
Your face takes UV year-round — on the drive to work, walking across a parking lot, on cloudy days in January. Up to about 80% of UV gets through cloud. A daily facial sunscreen or a moisturiser with SPF 30 is one of the highest-value habits there is, and it does more for how your skin ages than anything sold as an anti-aging cream.
Babies and kids
Under 6 months: keep babies out of direct sun where you can — shade, a wide-brimmed hat, and lightweight clothing that covers arms and legs are the main protection. If shade and clothing genuinely aren’t available, the AAP does say a small amount of sunscreen may be applied to exposed areas like the face and backs of the hands. (An earlier version of this article said no sunscreen at all before 6 months, which could leave a parent with a sunburned baby and no option.)
Over 6 months: sunscreen on all exposed skin, plus hats, sunglasses and swim shirts. Mineral sunscreens with zinc oxide or titanium dioxide are often gentler on sensitive skin.
And the thing sunscreen can’t fix
Avoid tanning beds entirely. There is no safe tan — a tan is the visible sign of skin damage that has already happened.
Sunscreen is one layer of protection, not a licence to stay out longer. Shade, clothing and timing do at least as much work.
For what to watch for on your skin and when to have a spot checked, see our article on skin cancer prevention and detection. We also do skin exams and biopsies here — call (417) 332-3639.
As always, I hope you stay happy and healthy.
Carolyn Clark, NP-C