Illnesses spread by ticks, mosquitoes, and fleas more than tripled in the United States from 2004–2016, going from 27,388 reported cases to 96,075, the Centers for Disease Control and Prevention reported yesterday. Tick-borne ailments such as Lyme disease accounted for more than 75% of reported cases. Warmer weather is a major cause for the explosion in these vector-transmitted diseases, The New York Times reports, as ticks thrive in areas once too cold, and mosquito populations mushroom during heat waves. Travel and trade to and from tropical locations where disease-carrying critters can survive year-round are also to blame. Because controlling the vectors is expensive and difficult, experts advise wearing long sleeves and pants, using repellant, and doing full body tick checks to protect yourself this summer.