Wearing a hardhat is recommended when collecting the fruit. Unfortunately, sans foam insert or hardhat liner, the recirculation of energy WILL NOT occur. Each person needs to have a hardhat, boots, sturdy clothing, and three sources of light. Cisco NX-OS is based on HardHat Linux. Merryman, Ace the Bat-Hound and Hardhat. Hardhat later appeared committing crimes in Opal City. Still later, Hardhat was seen among the "forgotten characters" of Limbo.