Frost Weapon Fusion
(from Starfinder Core Rulebook)
The frost fusion imbues a weapon with the icy cold of a dead world far from its system’s sun. Half the weapon’s damage type is replaced with cold damage. You can activate or deactivate the frost fusion as a swift action. If the weapon already deals two types of damage, replace one of them with cold (you decide which damage type to replace each time you activate the frost fusion). You can add this fusion only to a weapon that does not already deal cold damage. This fusion never causes a weapon that normally targets KAC to target EAC.