Just thinking about poison ivy can make you itch. Blistering rashes on your arms and ankles, oozing bumps between your fingers and eyelid-swelling exposures are all-too-familiar summer hazards.

"Hot and sunny" may seem like a good summer forecast—unless you get too much heat and sun. High temperatures and sun exposure can lead to skin problems like heat rash—a short-lived rash that resolves ...