Cuzco and Elevation

Cuzco sits at an elevation of 11 200 feet, and some people do suffer terribly from altitude sickness.  As soon as you pass through immigration at the airport the travel agencies are advising you to chew the coca leaves to help with illness related to the elevation.  We felt light headed, dizzy,and at times couldn´t seem to get enough air even at a resting state.  Our hotel also provided coca tea and leaves.