Caps and booties help stop the loss of body heat from an infant's head and feet (the two places where body heat is lost rapidly, causing a chill). You'll find a wide variety of cap & bootie sets. Caps may feature multiple knitted layers for additional warmth and no side seam to prevent chafing. Booties may include Velcro® closures, elastic at the ankles for a snug fit and large cuffs to tuck in pants.