Last year, around a third of grownups in the U.S. got a sunburn — often bad enough that it made it hard to wear clothes over that part of the skin. And it happened even though they knew how to protect themselves.

Part of the problem is that although people use sunscreen and big-brimmed hats around the pool or at the beach, they may forget when they sit outside at a cafe, go for a walk, or play tennis.

The result can be skin cancer.

Also last year, around 186,000 people in the U.S. were diagnosed with melanoma, the most dangerous form of skin cancer.

Basal cell carcinoma, the most superficial form, affected more than 3.5 million Americans from age 30 to over 65. While it can be treated easily, if overlooked it may spread.

Squamous cell carcinoma is the second most common form, affecting just less than 2 million. It can require more extensive surgery than basal cell carcinoma in order to remove cancerous cells and provide a margin of safety.

This spring and summer, go for cover. Use micronized zinc sunscreen with an SPF of 35 whenever you're outside.

You can also wear hats to protect your face and neck. Choose protective clothing (there are shirts and pants with SPF) and sunglasses with UV protection.

Between 10 a.m. and 2 p.m., stay out of direct sunlight if possible.

And get a skin check annually; to find a local board-certified dermatologist, go to aad.org/findaderm.