AFTER PRE-SHIFT INSPECTION AT THE DRAGLINE, EE WAS SITTING IN THE DRAGLINE OPERATORS CAB & TOLD CO-WORKER THAT HE HAD A HEADACHE. WHILE CO-WORKER WAS OPERATING THE DRAGLINE EE CAME BACK IN FR OM THE OILERS ROOM & TOLD CO-WORKER THAT SOMETHING ELSE WAS WRONG WITH HIM. REALIZING THE EE WAS EXPERIENCING PERSONAL MEDICAL CONDITIONS, CO-WORKER SHUT DOWN DRAGLINE & CALLED FOR MRT'S.