Here's some timely advice on the first official day of summer: Wear sunscreen.

But don't take my word for it. Take it from this guy, who got second degree burns after going sunscreen-less during a day of outdoor work. (Warning: it's not pretty.)

Now, if you're looking at these photos and thinking to yourself, "well, I'd never be so foolish, because I'm responsible about applying sunscreen," you should still take heed. You're probably doing it wrong: A recent study published in the Journal of the American Academy of Dermatology identified several common ways that people misuse sunscreen.

To conduct the study, researchers placed free sunscreen dispensers around the Minnesota State Fair and watched how about 2,200 people used them. There were three main takeaways:

1. Only about one out of three people applied the sunscreen to all of their exposed skin.
2. Only 38 percent of those who used the dispensers wore protective clothing such as hats or sunglasses.
3. Use of the sunscreen dispensers declined significantly during cloudy days—even though about 80 percent of the sun's UV rays penetrate clouds.

Taking extra precautions like these might seem like overkill, but in reality they're simple steps that can reduce your risk of developing skin cancer. It's estimated that one in five Americans will develop some form of skin cancer in their lifetime—and while genetic and hereditary factors can influence your individual risk, avoiding exposure to UV radiation from the sun by using sunscreen is an easy preventative measure you can take.

The researchers behind the Minnesota State Fair experiment offered some helpful tips to insure you're getting the most out of your sunscreen.

1. Choose a sunscreen with an SPF 30 or higher. While no sunscreen can filter out all of the sun’s UVB rays, SPF 30 sunscreens block 97 percent of the sun’s UVB rays.
2. Look for the words “broad spectrum.” This means the sunscreen will protect against both UVA rays (which cause premature skin aging) and UVB rays (which cause sunburn). Both types of UV rays can lead to skin cancer.
3. Look for the words “water resistant.” No sunscreen is completely waterproof, but water-resistant sunscreens can provide protection for wet or sweaty skin for 40 or 80 minutes, as indicated on the label. All sunscreens should be reapplied every two hours, or after swimming or sweating.
4. For sensitive skin, choose a sunscreen with the active ingredients zinc oxide or titanium dioxide. Those with sensitive skin also should avoid sunscreens that contain fragrance, oils and para-aminobenzoic acid, also known as PABA.