How Often Should You Apply Sunscreen If You're Swimming?

• Dermatologists say you should reapply sunscreen every two hours, especially when you're at the beach or outside for extended periods of time.
• You can still get a tan with sunscreen on because while sun creams block many damaging skin-burning rays, they're not as great at filtering out the milder rays, which penetrate deeper into the skin.
• Sunburns can lead to skin cancer, which is why it's important to wear some protection when you're exposed to the sun, whether it's at the beach, or on a stroll around town.

It's getting warmer out there, and that can only mean one thing: sunburn season is just around the corner.

Americans tend to be pretty terrible at protecting skin from getting burned in the summer sun. According to the Skin Cancer Foundation,  more people are diagnosed with skin cancer every year in the US than all other cancer diagnoses combined, making it the most common— and arguably one of the most preventable — forms of cancer.

The good news is that sunburns are avoidable if you know how and when to apply your sunscreen.

Some dermatologists will tell you that any sun exposure that changes the color of your skin is too much. After all, this is a sign that DNA damage is taking place in your skin.

Staying active and soaking up a little vitamin D isn't necessarily a bad thing, as long as you're minimizing sun exposure time, and protecting your skin with an SPF.

Scientific studies suggest that avoiding the sun at all costs is not a good recipe for a long and happy life. One 2016 longitudinal study  of more than 29,500 Swedish women found that the Swedes who avoided the sun altogether tended to die earlier than those who caught a few rays. Other recent research suggests  that a little time in the sun on a regular basis can be good for your bones, your mood, and your waistline.

Here are a few tips from the skin pros about how to enjoy the sun the right way:

Lathering up with sunscreen every two hours is a good benchmark, especially when you're at the beach or out all day basking in the sun's rays.

That's because a sunscreen's sun protection factor (SPF) value is only fully effective for two hours after you put it on. In other words, after two hours, your sunscreen isn't entirely doing its job anymore. For example, if you put on an SPF of 50 at 10 a.m., by noon you're probably still getting some protection, but your SPF 50 is no longer accurate.  More accurate is about SPF 10 at that point.

Speaking of SPF, The American Academy of Dermatologists  suggests sunbathers go with an SPF of at least 30.

People tend to be pretty good at lathering up their faces, but there are a few key spots that dermatologists say patients tend to forget while they're putting on cream: the neck, as well as the tops of the ears.

Those are common places doctors see skin cancer pop up, so don't neglect to give them a good rub. And if you don't have as much hair as you used to, don't neglect the top of the head, either. Everyone could probably use a little bit of cream on the scalp line to keep it from turning red, anyway.

Finally, don't rely too heavily on sunscreen sprays. They tend to disperse a lot of sunscreen into the air, instead of onto your skin, and what does land on your body tends to be a less even coverage layer than what comes out of a bottle of sunscreen.