It’s Friday night, and you’ve got the flat to yourself. You hear the muffled din of laughter over the thumping bass of an ambiguously Drake-ish song from the neighbors’ party downstairs, which your flatmate tried to convince you to hit up with her. Normally you’d be down, but you’re way too wiped from today’s brutal physics midterm (which, of course, you crammed for the night before). So you flop down on the sofa to cozy up with Netflix and a bag of spicy Cheetos.

First, Check for Alcohol Poisoning

When you drink alcohol, it enters the stomach and small intestine, where it gets absorbed into the bloodstream. Alcohol poisoning, a potentially deadly condition, can happen when alcohol in the bloodstream reaches dangerously high levels. To check whether your flatmate might have alcohol poisoning, remember the acronym “CUPS,” says Raeann Davis, a health promotion specialist at the University of California, Davis. Call 9-1-1 if they show any of the following symptoms:

C: Clammy or blue skin. U: Unconsciousness or inability to be roused—especially after you firmly rub their chest. P: Puking uncontrollably. S: Slow or irregular breathing.

You should also call 9-1-1 if your flatmate can’t walk or if their speech is unintelligible, says Scott Younguist, an emergency physician at the University of Utah Medical Center. Make sure to specify that you have a medical emergency to ensure the dispatcher sends an ambulance, not just a police officer.

Meanwhile, try to glean as much information as you can from friends or others who were with your flatmate about how much they drank, and if they were mixing drinks, or taking substances other than alcohol. “When help arrives, they’re going to ask those questions,” Davis says.

While you might worry about getting your flatmate in trouble, especially if they’re underage, many colleges and universities have adopted Good Samaritan policies that protect students from legal trouble if they call for medical assistance for an alcohol-related emergency. Even if your school doesn’t have such a policy, remember that calling 9-1-1 could save your roomie’s life. It might seem drastic, but they will understand you were acting in their best interest, Davis says.

Keep Your Flatmate Awake for an Hour or More

If your flatmate doesn’t seem to have alcohol poisoning, chances are they’ll be fine sleeping off the alcohol, Youngquist says. But if you want to be extra careful, try to keep them awake and alcohol-free for about an hour or two—roughly the maximum amount of time it takes for alcohol to absorb into the bloodstream—before letting them knock out, Davis says. If your flatmate’s blood alcohol levels are still rising, which can happen even when they’ve stopped drinking, it’ll be easier to spot signs of alcohol poisoning if they’re awake than if they’re asleep. And if they start vomiting, they’ll be much safer doing so while they’re awake.

Cut Them Off From Drinking

“No one likes being told they can’t have any more drinks,” Davis says, which is why this part can be tricky. So, more acronyms. She suggests remembering the three Ds: If your roomie grabs a beer from the fridge, you can be direct by taking it away and saying something like, “I really can’t give you any more. I’m concerned about you.” If that’s not your style, delegate the task of cutting your roomie off to a partner or close friend. Or, distract them—with that episode of ‘Forensic Files,’ or even a Coke or other non-alcoholic beverage if they insist on another drink, especially if they’re too drunk to notice it’s not spiked. “You don’t have to be direct,” Davis says. “There are other tools.”

Help Stay Hydrated With Lots of Water

Younguist says water or electrolyte drinks like Gatorade can help your flatmate flush out the alcohol by peeing it out. “They also dilute the concentration of alcohol in the bloodstream so its effects are lessened,” he adds. Plus, staying hydrated could help them feel less shitty the next day. Alcohol acts as a diuretic—meaning it makes you pee a lot—which can lead to dehydration. Dehydration, in turn, can contribute to headache, fatigue, and other hangover symptoms.

Fast Food Run

Besides tasting uh-mazing, a juicy cheeseburger can also help dull the effects of alcohol. Fatty foods in particular slow down the absorption of alcohol from the stomach into the bloodstream, since alcohol has a hard time traveling through fat, Youngquist says. That cheeseburger basically grabs hold of the alcohol molecules, “forming a cheeseburger-alcohol ball in your stomach.”

But Youngquist notes that this advice is only helpful if your flatmate has had a lot to drink, and their bloodstream is still absorbing alcohol, which could take as little as ten minutes. Once that happens, it’s too late for a cheeseburger to lessen its effects. While your roomie may seem more lucid after a cheeseburger run, if their bloodstream had already absorbed the alcohol by the time they started eating, “time was what sobered them up,” not food, Davis says.

A Strong Cup of Coffee

Contrary to popular belief, coffee doesn’t sober you up—that is, it doesn’t lower blood alcohol levels. But, “caffeine is helpful as a stimulant to counteract the sedative effects of alcohol,” Youngquist says. And “it may help prevent the headache of a hangover.” Alcohol dilates the blood vessels of the brain, leading to headaches; caffeine narrows blood vessels, he tells me.

If Your Flatmate Passes Out, Safe Positioning is a Must!

Roll your flatmate onto their side or stomach, not onto their back, Youngquist says. That way, in case they do start throwing up in their sleep, they’ll be less likely to choke on their vomit.

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Check While They're Asleep

You’ve kept your roomie awake long enough for their bloodstream to absorb all the alcohol they drank, and their blood alcohol levels won’t continue to rise in their sleep. If they keep nodding off—no matter how loudly you recount the plot of that freaky Forensic Files episode—let them sleep, but check for signs of alcohol poisoning every five to ten minutes (and pat yourself on the back for being a good friend), at least initially. “If they haven’t been drinking for 30 to 45 minutes, you’re probably ok to check less frequently,” Davis says.

Be Compassionate

Maintaining your cool could prevent the situation from taking a violent turn. If you take your flatmate’s drink away from them, Davis suggests explaining that it’s because you care about them, even if you’re annoyed. “Risks of assault can increase with intoxication,” Youngquist says. If you do feel threatened by your flatmate, don’t hesitate to call campus police.