Don't think pills is the answer...Check and insure there is a fan for cooling breeze...Flush system with lots of clean fluids and replace with fresh as indicated (50-50 phosphate free antifreeze and distilled water)...diagnose the temperature regulation (thermostat)...bleed the system, re-bleed the system, and again. Heart is circulating fluids (water-pump) and have you checked to ensure you don't have a bad thermometer (temp sensor)?