From Guild Wars 2 Wiki
Coolant Buckets are bundles used to assist Scientist Vratt by catching fireballs in the Fractured Caldera.
|1||Throw Coolant||¾||1||Throw coolant on floating data collectors to cool them down.|
|2||Catch Fireball||3¾||5||Used to catch falling molten rocks from the caldera.|
- Once picked up, the character is affected by 10 stacks of Coolant Bucket Charges; a charge is removed when using the Throw Coolant skill.