Something a little silly but say you're too cold to be nude. What do you put on? For me pants are always the first thing to go on and the last to come off but some will put a top on with no pants. Girls look hot in only a top or when they wear shorts so short that you can't tell they're wearing any but I personally think even the best looking man should leave the no pants look to Winnie the Pooh and Donald Duck.
If I'm nude and it gets too chilly I uso to put over a light fleece jacket. It warms good and feels like nothing. As long as it's not too cold you can leave the zip open. But of course this is not outfit for a fashion show or a more formal meeting.
The top is far more important/effective for cold protection: the torso contains the vital organs. But exposure to cold is an environmental hormetic, and may have anti-aging effects. So I often stay nude through cold beach winds even though my already-small penis quickly looks like a thimble. And how important is clothing appearance to a nudist? Clothing is not the person. It's not the girl who looks better in a top. The girl-top combination looks better because it shows her sexually-suggestive legs, but what the heck is a girl-top?
If I get chilly I cover my upper body with a robe or throw a bath towel over my body. Usually I let the robe hang open or the towel hang over my back as the covering on my back tends to warm me up. Think about how you get out to warm up under the sun. You usually turn your back to it.
I am not sure why anyone would have a problem with me wearing a shirt with no pants, but, if they did, they would likely not be a friend of mine. I do not choose my state of dress/undress based on fashion. Whether just my penis or just my chest is exposed really should not matter. I put on whatever I feel like that would make me less cold yet keeps me as naked as possible. ;-) I make a personal choice to have nonjudgmental friends and do my best to reciprocate that respect.
I often walk around home with only a tee-shirt if not totally nude. Depends on how cold I feel. I've had a couple FBs that seemed to like my t-shirt-only look when answering the front door.
I usually don't start with either. Instead, a cap! If you cover the top of your head and your ears, you'll be amazed at how much warmer you feel.