I'm a red head, too, and burn so easily. I found Neutrogenia Ultra Sheer by accident on Catalina Island, on our way to Mexico. I applied it before leaving and thought I'd tossed it in my bag. We took a catamaran to a private beach off Puerto Vallarta. The sun was hot, no shade and I reached for the Ultra Sheer. It wasn't there. No store, no extra clothing, I knew I'd just completely ruined the rest of my vacation. We stayed for about 3-4 hours and then another 45 minutes getting back to shore. The temp of my skin was HOT, I knew I was in big trouble. Guess what? No sunburn!!! It was the most amazing thing, expecially since the banana boat dumped us twice, I played volleyball, etc. I'll never be without it again.