Our Sun Shield Tee is silky soft, lightweight stretch jersey with a UPF-50 rating that blocks 98% of the sun’s harmful UV rays. It is not a chemical treatment - it's a mechanical quality of the yarn so the protection won't diminish with washing. Super comfortable indoors and out and perfect for all sorts of applications beyond sun protection too: skin conditions, wound care, topical medications, works great as an anti-anxiety calming aid that can be worn all day. They really reduce heat absorption too: We tested our black Lab, Luke, out in the sun with an infrared thermometer and found his fur was more than 40 degrees cooler under the Tee than without – it’s wearable shade! Want extra cooling? Get it wet and your pup can enjoy the evaporative cooling effect! Recommended For: Sun protection, regulating body temperature, indoor wear, outdoor wear, protecting skin conditions or wounds, mild anxiety, increasing cuteness