EE WAS CUTTING AND INSTALLING CHAINS INSIDE #1 KILN. CONTRACTORS WERE WELDING NEAR THE DISCHARGE END OF THE KILN, CAUSING FUMES & SMOKE TO MIGRATE INTO EE'S AREA. EE BECAME LIGHT-HEADED AND FELL 3 TO 4 FT. ONTO KILN SHELL FLOOR, LANDING ON CHAINS, BRUISING RIGHT LEG AND HAVING TROUBLE BREATHING.