JW411
There must have been something wrong with the guy other than a cold?
You can change 500 feet driving over a small hill in a car?
The total pressure of Air column on the surface of the earth is 14.7psi or one atmosphere.
As someone who Scuba dives that equated to every 33 feet down you go in the sea.
The person you had must have also had a severe ear infection to have experienced such severe pain at only 500 feet?
Pace