Question is as the title says, "Is there a way for a human barbarian to acquire the cold-honed half-elf racial trait?"
Maybe through feats or traits? Something adopted?
(The racial trait is available from the books Bastards of Golarian and Heroes of the Fringe.)
EDIT: It doesn't have to be exactly cold-honed, but instead just the ability to ignore snowy terrain and such.
Snowborn can move through natural snow and ice at their normal speed and gain a +4 racial bonus on Fortitude saves to avoid nonlethal damage from cold environments.