Back From The Dead

No, I really wasn't dead, just taking a hiatus. I am back though, and ready to write. I thought I would start out with a Medical Monday, even if it is Tuesday. Did you ever look at the SPF numbers on sunscreen? That stands for Sun Protection Factor, in case you didn't know. The higher the number, the more protection. Supposedly. You would think that meant if you had a high enough number, no sunlight would penetrate to your delicate skin. That's not exactly right. In reality, when you put on a lotion with a number like 75 it gives you the same amount of protection as a 15 SPF lotion. The real difference is the length of time the protection lasts. A 75 SPF lotion just puts on more of the same stuff, so it wears off slower but doesn't actually protect you any more than a lower number. A 15 SPF lotion might last for a couple of hours, but the higher number will last for three or four times as long.

Now you know.