I think you should maybe where very short shorts and a very light top or a light nightgown but make sure that it is not too showy. I really don't advise sleeping naked. Don't put a blanket on. If they have water bottles on the planes you can sleep with one close to you or under your pillow. There is air conditioning over the seats so you can turn that up and face it to you. You can also turn off the light over you. After all of this it might be a little hot but I strongly advise that you don't sleep naked. Its only one night and also if you have a cream that you put on your rash get it in a container that is small enough for the plain. Hope all of this helps! Have a good flight!

I have eczema, so I also get red rashes if it's too dry, hot, and I don't put on lotion often. When I was on a plane for 12 hours, I just brought a small can of lotion, and wore short shorts and a tank top because I could sleep in it and it wasn't too pajama like for in public. The place I was going to was extremely humid anyway, so what I wore was fine. You could wear a jacket over the tank top at the airport though.

 

My rashes are on the back of my legs and elbows though, so a tank top and shorts helped. But if your rashes are on your back or something, it might not work.