By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) - This is the time of year when we begin to focus more on skin cancer. This is one of the most common types of cancer, affecting more than two million Americans each year.

Having light skin, hair, and eyes increases a patient’s risk for skin cancer, as does over-exposure to ultraviolet rays at an early age.

It is important to counsel children, adolescents, and young adults aged 1 to 24 years who have fair skin about skin cancer prevention. The question often comes up about the effectiveness of suntan lotion with high spf. Certainly wearing an spf of thirty or better is helpful but you need to apply it often.

One of the problems with sun block is that people stay out in the sun much longer thinking they will be totally protected. That is a mistake.