EE WAS PERFORMING ROUTINE MAINTENANCE IN ALL AREAS OF THE PLANT. AT APPROX. 11:00 AM, THE AREA BEHIND HIS LEFT KNEE BEGAN STINGING. UPON INSPECTION, EE NOTICED THE AREA WAS SWELLING AND THROBBING AS WELL AS BEING RED AND IRRITATED. HE PRESUMED A SPIDER HAD BITTEN HIM. EE CONTINUED TO WORK. AS THE DAY WENT ON, THE SWELLING & PAIN INCREASED & HE WENT TO THE DOCTOR FOR TREATMENT.