Just because you aren't poolside or hanging out at the beach doesn't mean you shouldn't slather on sunscreen. Research from the University of Washington found that many cases of the deadliest skin cancers were found on the left arm and side of the face, and the increased cancer risk is likely linked to driving with the window down, the study authors concluded.

The U of Washington study, which looked at over 80,000 cases of skin cancer, also cited an earlier study from Australia—where drivers are on the left-side of the road—that found the same pattern on the right side of the body. Furthermore, the new research supports 2010 findings from St. Louis University that found malignant melanomas occurred on the left side 74 percent of the time.

When the sun is the strongest and the UV index reaches "solar noon," says the Los Angeles Times, all it takes is 10-20 minutes of exposure for the most sensitive to get skin damage. Usually, rush-hour periods aren't at solar noon, but exposure to UVA rays, which can penetrate office windows too, can accumulate over time. 

According to the Canadian Cancer Society, skin cancer is the most common cancer in Canada. The risk of developing skin cancer in our lifetime is one in three. For summer road trips, remember: Even driving with the window up increases your exposure to UVA radiation. Cover up with a long-sleeved shirt, and slather on sunscreen if you're headed out on the road. Toronto dermatologist Dr. Paul Cohen told Best Health, “SPF 15 is good if you’re inside most of the time." Wear sunscreen with at least SPF 30 when you're outdoors.

Related:
• New online: An interactive way to fight skin cancer
• Are Canadians at higher risk for skin cancer?
• Are all sunscreens safe?