I keep a fly mask on my horse, daily, while in the sun. I only used this brand for special short term occasions because it is so cute. My main fly mask i use everyday (another brand) was dirty so i put this brand on and used it for several days in a row. The temp was in the upper 90's. My horse ended up with a blistered face, to include the sides of his face/head - which included white/pink skin and chestnut/dark skin areas. The one i used was purchased 3 years ago.