THE EMPLOYEE WAS DRIVING A HAUL TRUCK. THE AIR CONDITIONING UNIT IN THE HAUL TRUCK WAS NOT WORKING PROPERLY. EMPLOYEE NOTIFIED FOREMAN TO INFORM HIM THAT HE WAS NOT FEELING WELL. AFTER BEING E XAMINED BY AN ONSITE EMT, IT WAS DETERMINED HE WAS EXPERIENCINF HEAT EXHAUSTION, AND HE WAS THEN TRANSFERRED TO THE HOSPITAL.