This article was created in partnership with Delta x Equinox Sweatlag.

So you saved up, made plans, packed your bags, and finally landed at your destination… first up on the agenda? Spend the next few days as a walking zombie fighting off a bout of jet lag so strong it feels like you popped a sleeping pill and washed it down with a shot of whiskey.

Is this how you really want to spend your vacation? Or worse, the first few days back when your mile-long to-do list means you need to be alert more than ever? We didn’t think so.

We teamed up with our friends at Delta to figure out what exactly jet lag is, what causes it, and how to fight it. Delta is now flying its new A350 plane, which actually reduces jet lag’s impact through wider windows, improved air quality, and fancy LED lighting technology. To arrive even more refreshed, reserve a Delta One seat, where direct aisle access, fully reclining seats, and sliding doors let you snooze in comfort. Because travel is supposed to be full of fun, not fatigue.

So What Exactly Is Jet Lag?

Ever wonder why you generally wake up and get tired around the same time every day? That’s thanks to circadian rhythm, an internal biological clock set on a 24-hour loop. It’s mostly impacted by sunlight (there’s a reason curtains were invented) and our daily routines, and it’s what keeps us on a regular schedule. Unsurprisingly, when we cross several time zones quickly, our body clocks need time to catch up and adjust to the new destination. The time it takes for our bodies to make that adjustment—and the resulting symptoms from our schedule being out of whack (fatigue, headaches, irritability, sleep disruption)—is our dear friend jet lag.

While it’s not entirely avoidable, there are plenty of crafty, science-backed ways to lessen jet lag’s effects. Since the intensity of your symptoms depends on how far you’re traveling (we’re talking the difference between a mild wine headache and a full-on hangover), we created the map below to help you better prepare for your next trip. Choose one of Delta’s destinations in the time zone you’ll be traveling to—we’ll show you what you’re up against and give you some handy tips for kicking jet lag to the curb.