I suppose the length of time of confinement might have something to do with it, kmar, but I know that it only takes a few seconds to set mine off. Elevators and airplanes (even flying for 12 hours from Colorado to London) don't do it, but hanging upside down over the back of the washer in the small space between the appliance and the wall (I was retrieving a fallen sock) is guaranteed to trigger claustrophobia in about three seconds.
