How much sunscreen are you using? Hint: it's not enough!

AUSTIN (KXAN) — This time of year, you hear us telling you all the time not to forget to apply sunscreen. But how much should we be using, and what does SPF mean?Meteorologist Sean Kelly spoke with Dr. Aleksandra Zajac, who is a medical skin expert.Zajac said the sun produces three types of radiation: UVA, UVB and UVC. UVC is the most dangerous, but never makes it down to earth. UVA is responsible for skin aging and skin cancers, while UVB causes sunburn."This is the type of the sunlight t