When it comes to winter play, layering is tricky Too many layers and theyll overheat; too few and theyll freeze their tushes off. According to Catherine OBrien, a research physiologist with the U.S. Army Research Institute of Environmental Medicine, the key to keeping kids dry is conserving heat while still letting steam escape.

How to do that? The American Academy of Pediatrics recommends dressing young children in one more layer of clothing than an adult would wear in the same conditions. Start with a thin inner layer to wick moisture away from the skin. Avoid cotton, which soaks up sweat and holds it against the skin, accelerating heat loss; try a lightweight polyester or polypropylene fabric instead. Add two insulating middle layers (maybe a long sleeved top and leggings) of similar materials, keeping them a little loose to trap insulating air between fibers. Top it all off with a wind and waterproof outer shell.