If you wear a pullover, you won't feel cold. If you don't wear a pullover, you'll feel cold. (This one was already done correctly in your example)
You'll get wet, unless you take your umbrella. If you don't take your umbrella, you'll get wet.
You'll be late for school unless you get up now! If you don't get up now, you'll be late for school!
You won't get lost if you take a map. Unless you take a map, you will get lost.
If we don't feed the cat now it will get very hungry. (use "unless") The cat will get very hungry unless we feed it now.
If it doesn't rain, we'll go for a walk. We won't go for a walk if it rains.