Have you ever hesitated before diving into a pool, trying to remember if it's been at least 30 minutes since you ate? Or not itched a mosquito bite for fear that scratching would only make it worse?
Health myths buzz around summer pastimes -- such as swimming, camping, hiking and picnicking -- like so many gnats.
People have a hard time letting go of word-of-mouth wisdom, even when faced with good evidence to the contrary.
"Myths stick with us because they make sense to us, on some level," says Indianapolis pediatrician Rachel C. Vreeman. "When you've heard them from your grandmother and mother and important adults in your life, you believe those things."
Vreeman and fellow Indiana University School of Medicine pediatrician Aaron E. Carroll published studies in 2007 and 2008 debunking medical myths that doctors believe. Among them: Hair and nails continue to grow after a person has died. Shaving causes hair to grow back thicker. We use only 10 percent of our brains. Reading in dim light ruins your eyesight.
The studies received so much media attention that the doctors turned them into two books debunking many health myths: "Don't Swallow Your Gum!" and "Don't Cross Your Eyes . . . They'll Get Stuck That Way!"
"It's fair to ask 'Why?' when someone tells you you shouldn't do something, even if that someone is your doctor or your mother," Vreeman says.
Remembering the many warnings that swimming and outdoor activity inspire, we dug into some of the most pervasive summer health myths to find out whether they're true.