"Whether you’ve checked into a luxury resort, a modest motel, or an Airbnb apartment, spend a few minutes inspecting the beds and surrounding areas for signs of bedbugs."

"Pull back the sheets and look closely at the surface, sides, and seams of the mattress near the headboard. 'That tends to be the hottest area of the bed' for bug activity, said Dr. Potter. Dr. Miller suggested running a sticky lint roller over the areas you’re checking, so you can pick up any potential evidence. Pack a small, strong flashlight to help you see into crevices and behind the headboard if possible....  'We know in hotels that bedbugs like to get behind the headboard. The reason for that is it’s the least disturbed area,' Dr. Miller said. Though small, bedbugs and their fecal spots are visible to the naked eye, so if you don’t find anything after a cursory inspection, you can rest easy. 'I’m not going to yank the whole bed apart, flip the mattress,' Dr. Potter said. Dr. Miller agreed: 'If you don’t see anything, nothing’s there.'"

From "How to Keep Bedbugs From Coming Home With You/Bedbugs peak in the summer, just in time for vacation. Here’s how to check your hotel bed for bloodsuckers — and what to do if you find them" (NYT).

There you have it: Pack your lint roller and strong flashlight. Don't yank the whole bed apart, but you have to pull back the bedding and look at the seams of the mattress up at the top, "the hottest area" (that is, where your head will be).