Workers at a budget hotel chain are being given advice on how to deal with naked sleepwalkers.
It follows an increase in the number of guests found wandering around in the night with no clothes on at Travelodge hotels.
A study found a seven-fold increase in sleepwalking customers in the past year, to more than 400 cases – almost all of them men.
Many sleepwalked naked into the reception area asking for a newspaper, or saying they wanted to check out.
One naked guest was arrested after being locked out of the hotel.
Chris Idzikowski, of the Edinburgh Sleep Centre, said: "These figures are a surprise.
"Sleepwalking can be triggered by a stressful lifestyle, sleep deprivation, alcohol abuse or not breathing properly during the night."
Travelodge said it was sending a guide to its staff on how to deal with sleepwalkers, such as keeping a supply of towels in reception to help preserve a guest's dignity.
Leigh McCarron, Travelodge's sleep director, said: "We have seen an increased number of cases over the years so it is important that our staff know how to help sleepwalkers when it arises."