Kids love a good walk through the woods to get away from the hot summer sun. If you go off-trail, though, be sure to keep a look out for poison ivy. Some studies suggest that global warming is contributing to the growth of poison ivy and its ability to produce its itch-causing oils.

Whether or not that's true, it is a fact that you want to stay far away from the stuff. Poison ivy grows in open fields, on roadsides, at the beach, even in your backyard. The general rule is, "Leaves of three, let it be." But there are a lot of three-leaved plants around, so it's a good idea to know what poison ivy looks like.

Poison-Ivy.org is an excellent resource for learning how to identify poison ivy. Start with their quiz, then work your way up to their FAQ. If you think you're already a poison ivy expert, check out their advanced page to see how creative poison ivy can be. If you really need motivation to learn more, check out their skin rash hall fame (but not if you're squeamish, it's pretty ugly!)

%Gallery-24601%If you or your little one do get into a patch of poison ivy, Dr. Greene has some great tips for relieving the itch. The Poison Ivy, Oak, and Sumac Information Center has an extensive list of commercial, medical, and home treatments for poison ivy. Many of these are reader-recommended, however, so take each one with a grain of salt.

Once you're exposed, the rash will appear in 12 to 48 hours and will last 2-3 weeks. The urushiol (the oil that causes the rash) is absorbed into the skin quickly, so the rash typically is not contagious and doesn't spread to others or to other parts of the body. Any severe rash should be seen by a doctor, as should any highly allergic individual following exposure.

Summer is a great time of year to commune with Mother Nature. Educating the whole family on how to recognize the "leaves of three" will help keep that outdoor time safe and itch-free.