In this month's episode of Field Notes , Susan Knight of UW-Madison’s Trout Lake Station talks about that annoying summer problem, “Swimmer’s Itch” and how we can avoid it. Last September, I was on one of my favorite lakes collecting aquatic plants for plant identification workshops I present over the winter. Later than night, my hands started to itch, and I could see little welts all over my hands and arms. Swimmers Itch! I haven’t had this too often, and since only my hands and arms were