Because some dipshit lady almost killed her 10 year old boy two years ago. She bought into the whole sunlight is evil hoax. She used so much sunblock on her kid that he was severely vitamin D defficient. It took ten doctors to figure it out. Actually one doctor. The others were mainstream ignormaouses like most people.

My kids are the same age as the Op's. They NEVER get sick. And i really mean never. In florida when they shut schools down for flu outbreaks my three are healthy as can be.

Sunblock causes cancer. Just so you know. Theres some wicked chemicals they put in there. Plus your kids need sunlight. Not just for ten mins on their faces. This time of year they should have a good body tan. That'll fix them right up.