What you do is look at what gear your wearing and how much it covers and warmth it gives.
If your well over fine in torso, cutup the shirt, to make something to cover the mouth, and hand/foot wraps etc.
A long scarf is awesome to make because if you only grab a weapon.
You shouldn’t freeze in the shelter, not with crates and things to burn. It’s very easy to make a hammer/crowbar and other tools in the shelter.
If you absolutely ‘need’ gear make some ventures out to find a zombie or 2 running around, kill it, take the clothes off it to either wear or cutup. I usually have a spiked pits waiting to assist in killing critters/zombies.