Winter is here, so in this video I break down Layering 101 the way I actually use it on cold-weather hikes. I walk through the three-layer system—base, mid, and outer—and what each one is supposed to do: the base layer wicks moisture, the mid layer insulates, and the outer layer acts as a shell that blocks wind, rain, and cold. The big takeaway is that layering isn’t just “three jackets,” it’s a system where each piece has a job. For base layers, I explain why “cotton kills.” Cotton absorbs water and holds it against your skin, which makes you cold fast. Instead, I look for wool (less stinky, but more expensive) or synthetics (cheaper and common, but can get stinkier). For mid layers, I talk about why puffy jackets with down are so popular for trapping heat—while also warning that you can absolutely overheat if you bring something too warm for your conditions. And for shells, I share my opinion that Gore‑Tex works really well for jackets, as long as you buy what matches your environment and don’t overspend for your actual use case.