Initially they were much longer, and housed in a backpack in the original and much cruder design of the coolant suit. It appeared that Scorpius has gotten Peacekeeper engineers to perfect the technology, making the rods much smaller so they could be placed directly into his brain, increasing their effectiveness. Cooling rods appeared neon blue when fresh and neon red when spent. During Scorpius' stay on Moya, Sikozu made new cooling rods for him. These cooling rods were apparently less efficient than the usual rods and tended to emit smoke when Scorpius was under stress.