Two skincare pros answer all of your burning questions. Julia Paolercio Updated (Photo: Supergoop!) Whether you’re concerned about sunburns, skin cancer or premature signs of aging, wearing sunscreen every day is the best thing you can do for your skin. But how exactly does it protect your skin—and how do you pick the best formula for your needs? We asked Dr. Monica Li, a Vancouver-based dermatologist and clinical instructor at the University of British Columbia’s Department of Dermatology and Skin Science, and Dr. Jennifer Beecker, a dermatologist in Ottawa and the vice-president of the Canadian Dermatology Association, to answer all our burning questions about SPF.