Pick a hotel that doesn't have carpeting or rugs, has metal framed beds, and if possible has encasements around both the mattress and the boxspring (an encasement is a fabric cover that completely covers the mattress or boxspring and is zippered closed). In other words, less places for the bugs to hide.
When you check in, examine the seams all around the mattress and boxspring (especially if they don't have encasements) for dark brown spots.
There are probably other better tips online. Good luck!