Gets Hot!
(Rule)Description: Roll to hit as normal, except that you must roll to hit even if the target is found to be out of range. For each result of a 1 rolled on its to hit rolls, the firing model suffers a wound (normal saves apply). Because of their additional cooling systems, weapons on vehicles are not affected by this rule.
Blast weapons do not roll to hit, so you must always roll a D6 before firing a Gets Hot! blast weapon to check if the weapon overheats. If you roll a 1, the weapon gets hot, it does not fire, and the firing model suffers a wound (normal saves apply). Otherwise the shot is resolved as normal.