I'm quite cold-tolerant, but I would hardly consider below freezing (0C) to be T-shirt weather. I would need 3+ layers to feel comfortable in that long-term. I

I'm quite cold-tolerant, but I would hardly consider below freezing (0C) to be T-shirt weather. I would need 3+ layers to feel comfortable in that long-term. It's only T-shirt weather if you're moving from one heated space to another.