Heat Wave is a revolutionary yarn that is activated by sunlight, even on a cloudy day, to keep you up to 12 °F warmer. Upgrade your outdoor gear and stay warm at sporting events, everyday outside activities or even walking your dog. Made in the USA, Heat Wave features a classic and versatile range of solids. Printed shades come in a variety of colors that can be used on their own or mixed with Red Heart Heat Wave solids to create new multi-colored projects for the whole family.