It's tick season again: 80 percent of Lyme disease cases occur between May and August. If you're vacationing in the Northeast this summer—anywhere from Maine to Long Island—pack your bug spray. Though the illness has spread to the upper Midwest, northern California, and Oregon, it's still most prevalent in and around New England. We asked Dr. Norman Brachfeld, medical director of On Call International, a New Hampshire-based travel assistance service, for his tips on how to deal with ticks: Avoid areas with a lot of brush; walk in the center of a path, not on the sides. • Ticks—the size of a period—are easier to spot against light-colored clothing. • Wear long sleeves and tuck your pant legs into socks or boots. • Repellents containing 20 to 30 percent deet (10 percent or less for children) are most effective; use permethrin (a common insecticide) on clothes and shoes—it kills ticks on contact. • Dogs pick up ticks easily, so if you take yours into the woods, brush him off immediately. • Performing regular tick checks is important as ticks don't adhere very tightly to the skin for the first 24 hours; a hot shower or bath may even wash them away. • Don't try to pick a tick off with your fingers—the head and mouth will remain in your skin, spreading bacteria. Grasp its head with fine-tipped tweezers, pull it out very gently, and dispose of it. • Seek a doctor's attention immediately if you develop the tell-tale bull's-eye rash of Lyme disease.