Patrick Sweeney, a tech entrepreneur turned adventure junkie, swears by the miracles of hyperventilation and cold therapy — and yes, it’s as weird as it sounds. “The way to do it is turn the shower on, take in 30 breaths as quickly as you can — it should feel like you’re sprinting and trying to get as much air as possible — then hold your breath for 30 to 60 seconds as you hop in the shower under the cold water,” he says. You then breathe deeply under cold water for about three minutes. According to Sweeney, it uses your fight-or-flight response to repair the damage of the hangover. Or maybe it just wakes you up a little bit. Either way, worth a shot.