Cold hands send more hunters home early than any deer ever did.
The layering thing isn't complicated but people get it wrong every year. The hike in gets you sweating. The sit drops your temperature fast. The morning that started at 28° is 52° by 10am and you're either comfortable or you bailed an hour ago.
Base layer: not cotton. Merino or synthetic, something that moves moisture off your skin. Wet cotton in a cold stand is a quick sit. This isn't a preference — it's just physics.
Mid layer: heat retention. An 8oz fleece hoodie is the practical choice for most whitetail hunting. It breathes enough for the walk in, holds heat in the stand, and it's quiet. Puffy jackets are loud. If you're moving at all, it matters.
Outer layer: wind. Cut it. Light moisture too if you can. Doesn't have to be your warmest piece — that's what the mid layer's for.
The detail most people miss: bring a dry base layer in your pack. Hike in sweating, switch to a dry one in the stand. You'll stay comfortable three hours longer.
Figure this out before September. You don't want to be diagnosing it at 6am when something's moving.