I use one of these when I travel, to but on top of beds so I can sleep inside it. They have two different sizes. The regular one is big enough for average size people. For how thin they are they keep you warm. And it's easy to wash in the sink. And compacts down to nothing in the mini stuff sack it comes with.

I spray the outside of mine with permethrin (the type for clothing) to help keep mosquitoes or other bugs off, just in case.

But this should work fine to lay over a business/first class seat. Thanks for the idea, I have a flight in business class next year, and I'll make sure it's packed in my personal bag!

Cocoon Silk TravelSheet https://a.co/d/7Z4SllR

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Edit: Here's a cheaper one that should work the same


Browint Silk Sleeping Bag Liner, Silk Sleep Sack, Extra Wide 87"x43", Lightweight Travel Sheet for Hotels, More Colors for Option, Reinforced Gussets

https://a.co/d/6nNP7Ph