Three things share a bed that strangers slept in. Bed bugs are reddish-brown and apple-seed sized, and don't live on you. They hide in cracks within about five feet of the bed and crawl over to feed at night ¹. They don't spread disease ², but one fed female can start an infestation, and they hitchhike well. Second: dust mites in the pillow and mattress, whose droppings are the real allergen behind morning congestion ³. Third: a fungal load, with Aspergillus recoverable from pillows one to twenty years old ⁴.

Bathroom counter first, bed second. The suitcase never touches the bed or the floor near it while you check. That contact is the pathway you're preventing.

Two groups should build this into muscle memory. Frequent travellers, because a low single-trip risk stops being low once you multiply it across a hundred nights a year. And anyone dust-mite reactive or asthmatic, for whom the exposure is the pillow, not the bug: a packable pillow cover and a $30–60 sleep liner separate waking clear from waking half-symptomatic ⁷.

The best payoff is one you never see. The first few trips it feels self-conscious to flip a mattress corner with the door open. By the fifth it's just the thing you do between dropping the bags and finding dinner. The reward you'll never notice: the infestation that didn't happen because the dryer killed the hitchhiker in the laundry basket. For sensitised travellers it shows up inside the trip — you sleep through, your eyes don't water, and you arrive at the wedding rested instead of taxed by the pillow.