Did you pick up some free sunscreen at the State Fair two years ago? Did you have the eerie sense that someone was watching as you slathered it on?

Fear not: It was a dutiful scientist from the University of Minnesota.

A U research team gave away sunscreen at fair information booths in 2015 in an experiment to see if people really protect themselves against sunburn and skin cancer as doctors recommend.

In results released Tuesday, they said the answer is often no.

For one thing, many fairgoers were duped by cloudy conditions, applying less sunscreen on one overcast day when the UV index was still in the high range.

“You can still get a sunburn if it’s a cloudy day,” said Dr. Ingrid Polcari, a dermatologist and a lead author of the study, which was published online and in the Journal of the American Academy of Dermatology. “In fact, it’s a high risk time for it, because people are more likely to relax and less likely to protect themselves.”

They also found that women were more likely to apply the sunscreen than men.

And that only 33 percent of people in the study applied the giveaway sunscreen to all exposed parts of their bodies, though researchers had no way of knowing whether they were being careless or had already used sunscreen earlier in the day and were reapplying.

The observational study of 2,187 fairgoers supplements the existing research on use of sunscreen, most of which is based on people self-reporting their usage.

Polcari said the goal was to encourage more regular use of sunscreen, especially in fair-skinned Minnesota where the intermittent spells of intense sunshine leave more people prone to sunburn, which in turn leaves more people at risk for skin cancer.

The rate of melanoma, the most deadly form of skin cancer, has more than doubled in Minnesota since 1990, according to the Minnesota Department of Health.

Minnesota recorded 27.8 melanoma cancers per 100,000 people in 2013 — fourth-highest in the nation, according to the U.S. Centers for Disease Control and Prevention. The state’s melanoma death rate, however, was closer to the national average.

“Don’t get sunburned when you’re out on a fun summer day,” Polcari said. “The State Fair is a perfect example of that. Everybody lets loose. They bust out their tank tops” and don’t take precautions.

The idea for the observational study came from then-medical student Megan Wood, who is now a doctor at the University of California San Diego. With the permission of fair officials, observers monitored sunscreen usage at four giveaway booths spread across the fairgrounds. They kept their distance so as not to be rude or obtrusive, Polcari said.

“I was wearing my sun hat and my sunglasses,” she said. “But no, I wasn’t wearing a weird disguise or anything.”

Rochester-based Pharmaceutical Specialties Inc. donated SPF 30 Vanicream sunscreen for the research.

Free sunscreen giveaways continued at the fair in 2016 — minus the scientific observation.

Polcari said she hopes that giveaway continues as a public health strategy to protect people.