well I would say using the cayenne pepper and garlic, we had a couple weeks where we hit -37 with wind chill and didn't add any heat and our flock is doing fine, roosters got frost bitten combs but that"s cause they don't come in much, always patrolling to make sure nothing gets close to their hens. during the winter we add in more yogurt and warm oatmeal along with a little cooked meat , along with giving them veggies that aren't gonna get used in time so they are pretty happy campers.