EE was operating a 745C truck,& was swerving for an 1/8 of a mile. As ee approached the top of the pit ramp, ee was seen by the oncoming operator to be slumped over in truck. As ee coasted down the ramp, the truck stopped as the front left tire came into contact with the toe of high wall. An operator put the truck in park, & woke ee. EE has low blood sugar.