I too have been dealing with sunburns but due to the fact I pasture board my horse at a boarding facility and have small children I am limited on being able to check on my horse while wearing a thin mesh sheet.I am afraid that the sheet will get lost or that the horse will get tangled in branches with it on. I have found good sucess in using childrens sunblock that is waterproof and sweatproof. I usually buy the NO AD with the highest SPF and it works well and is cheaper. I tried the fly spray with the sunblock but that did not work. When I apply the sunblock I put it on heavy and reapply it after it rains and or every three days whichever comes first. I have also noticed that I only need to do this in the month of August. But I still do light sunblock throughout the summer. Good luck.