Definitely not especially with you being in Texas. We're in Michigan and we don't use them. None of our chickens ever got sick or died from the cold. They even go out ON the snow. We've never use petroleum jelly on their combs/wattles either. One year a sex linked chicken's comb got a tiny bit frostbite, but didn't seem to affect her mood/appetite/energy level, and by mid spring it was gone.