A wellbore perforation gun includes a gun housing, a plurality of charges, a first reactive material, and a second reactive material that is reactive with the first reactive material to generate an endothermic chemical reaction to drop the potential energy (in the form of temperature or pressure) of the gun housing. The perforation gun may further include a controller and a release capsule, with the first reactive material being disposed within the release capsule and the second reactive material being disposed within a chamber of the gun housing at a first time. The controller may be communicatively coupled to the release capsule and operable to generate a signal to the release capsule at a second time that is later than the first time. The release capsule may be operable to release the first reactive material into the chamber response to receiving the signal.