If you’re thinking about, or are in the midst of, long-term travel, a silk sleeping bag liner is really an essential tool for you.
For a start you’ll always be sleeping in something that is yours. Silk sleeping liner can be washed easily while abroad, it weighs nothing and compact enough to put in a backpack. The main reason I would recommend one is that by sleeping in a sleeping liner you can avoid being bitten by mosquitoes or bugs. They are comfortable to sleep in when it’s hot as they are breathable. For this reason I would also recommend a silk sleeping bag liner as opposed to a cotton one as this will be too warm.
Taking the silk sleeping bag liner with you, you don’t have to confront a yucky bed or to be subjected to rather dubious bed sheets.