Driving with the window down and the sun shining on your arm carries a steep price in the form of an increased risk of skin cancer, dermatologists warn.
A study in the Journal of the American Academy of Dermatology looked at nearly 85,000 cases of skin cancer, and concluded more cases involved the left arm and left side of the face.
"This was greatest on the arm, and that pattern is exactly what you would expect from driving a car and the UV exposure you would get from that," said study author Dr. Paul Nghiem of the University of Washington.
Halifax resident Jon Stickney drives a bright red 2010 Mustang GT with the window down to enjoy the breeze,
"I get burned really easy," Stickney said. "I'd probably say on a daily basis almost, especially if it's on a longer road trip."
If Stickney were driving in a country where people get behind the wheel on the right side of the road, the reverse would likely be true.
Nghiem said they observed the opposite pattern with certain types of skin cancer in Australia, where driving is done on the left-hand side of the road.
Sunlight accounts for one in 10 skin cancers on the arm, said Nghiem, who advises keeping the window rolled up and wearing long sleeves.
Dr. Lisa Kellett, a dermatologist in Toronto, agrees with the advice, noting that closing the car window helps reduce the risk, but that some UVA radiation can still penetrate through the glass and cause skin cancer.
And while left-side skin cancers are more common in men, Kellett expects the pattern will change.
"Now with more women drivers, I would suspect the gender gap will close, and we'll see high reports of left-sided skin cancers in women in the future," Kellett said.
Kellett recommends everyone, particularly children, apply a broad-spectrum sunscreen of at least SPF 30 every day, whether in the car or not.