|Primary User(s)||Ko-Matoran, Ta-Koro Guard|
|Primary Location||Ko-Wahi, Ko-Metru|
Heat stones were similar in appearance to the crystalline lightstones, but produced less light, and much more heat - enough, in fact, to instantly melt ice. To contain this heat and make it safe to hold, the actual stone itself was contained inside a handheld, heat-retentive metal canister resembling a miniature version of those which had held the Toa Mata, albeit with four holes in the domed cap instead of six. This lid could be easily removed to access the heat stone's warmth, and was kept shut when not in use.
When heat stones were first discovered and used by Matoran is unknown, but they were commonly used as handheld tools in Ko-Wahi during the millennium in which Makuta started attacking the Matoran of Mata Nui.
One such heat stone was used by the Ta-Matoran who manned the outpost at the North March in Ko-Wahi; they were later assaulted by Makuta and massacred, and the Heat stone was one of the few things that remained intact in the abandoned outpost. A wandering Matoran named Takua - who had been enlisted by the Guard's Captain, Jala, to investigate the loss of contact with the outpost - came across its ruins and salvaged the stray heat stone. Shortly afterward, he used this stone to melt an icy glacier behind which a Ko-Matoran named Kopeke had been frozen. This particular heat stone was discarded and abandoned by Takua during his escape from a swarm of newly-awakened Lehvak when he was searching for the tool that would help him escape from the Bohrok Nest.Another heat stone was in the possession of an Onu-Matoran inventor named Nuparu during the Gahlok attack on Onu-Koro; when he and two other Onu-Matoran, Taipu and Onepu, got trapped in a cave-in, Nuparu used his heat stone to power a welding tool that he used to construct the Boxor from spare Bohrok parts.
All heat stones were abandoned by the Matoran after they evacuated to Spherus Magna.
- Members of the Ta-Koro Guard who had been stationed at the North March (all deceased)
|Matoran tools (v|e)|
|Mata Nui:||Ta-Koro Guard Spears • Ta-Koro Ensign Badges • Flute • Pickaxes • Icepicks • Kolhii Shields • Kolhii Sticks • Bamboo Disks • Heat Stone|
|Metru Nui:||Kanoka • Kanoka Launchers • Firestaffs • Tridents • Hammers • Chronicler's Staff|
|Voya Nui:||Resistance Team: Twin Repellers • Twin Chargers • Shredder Claws • Power Carvers • Pulse Bolt Generators • Echo Forks|
|Mahri Nui:||Air Launchers • Electro-Blades|
|Karda Nui:||Rocket Boosters • Power Swords|