You can make traps as if they were a higher level.
Benefit: A heightened trap has a higher trap level than normal (up to a maximum of 6th level). Unlike other metaconstruction feats, Heighten Trap actually increases the effective level of the trap that it modifies. All effects dependent on spell level (such as saving throw DCs and ability to penetrate a lesser globe of invulnerability) are calculated according to the heightened level.
Path of Iron, © 2015, Ascension Games, LLC; Author Christopher Moore