Most people love sunny, warm days, when they can get outside for fun and soak up the sun. But sun is one good thing you can have too much of – and not even know you've had too much until much later, when, like 80,000 Canadians every year, you're diagnosed with skin cancer. Fortunately, the majority of cases of skin cancer diagnosed are less aggressive forms called basal cell or squamous cell cancers, which are fairly easy to treat. But more than 5% are melanoma, a more serious form.