Coffee shops are, for many, the home office — at least until that fateful day when you spill your latte all over your laptop. The liquid can destroy electronics quickly, but your computer may be salvageable if you act fast.

Turn It Off Right Now

“First of all, don’t panic,” said Joe Silverman, owner of New York Computer Help. “The first thing to do is actually unplug the power cable, then hold down the power button for five to seven seconds until it’s totally off. Don’t waste the time properly shutting down.” If the computer is left on, even for a few extra moments, you could cause a short circuit, leaving the components inside with permanent damage. The quicker you can turn off the machine, the better chance you have of saving the computer.

If you can easily remove the battery, that should be your next step. Some laptops still have batteries that come out with a simple latch, while others make you unscrew the entire backplate to access the battery. If you’re comfortable doing so, go ahead and open it up. Otherwise, leave it closed. Remove any USB drives or dongles plugged into the laptop as well — you want to make sure nothing is trying to draw even a trickle of power from the system.

In addition, “Safety is the first thing that typically goes out the window when you’re in a panic,” said Kay-Kay Clapp, repair analyst at iFixit. “But I can’t tell you how important it is to remove yourself from any potential shock hazard — especially if you’re standing in water or your clothes are wet. If that’s the case, rather than trying to unplug it from the wall, find the circuit breaker or switch for that source of power and switch it off from there. If you see (or feel) any heat, smoke, steam, bubbling, bulging or melting, avoid handling the device.”

Once the device is off and you’re sure the area is safe, you’re ready to do some cleanup.

Turn It Upside Down and Let It Drain

Take a dry cloth and wipe up any excess liquid from the surface of the laptop — especially near the keyboard, vents or ports — and open the lid as far back as it will go. Turn the laptop upside down, put it over a towel or something absorbent, and let the water drain out of it. You don’t have to open the laptop if you aren’t comfortable doing so, but if you are, remove the backplate and wipe off the components with a lint free cloth before letting it sit to drain.

“I tell people to leave it 24 hours if you can,” Mr. Silverman said. “That’s ideal. If you don’t have the time, I’d say a minimum of four hours. Even though it seems dry, these parts do absorb a lot of water, so that just gives it time to dissipate any liquid.” The longer you can let it sit, the better. But if you absolutely have to use your laptop for work, Mr. Silverman said their testing shows four hours to be a pretty decent amount of time.

And despite what you may have heard, open-air drying is best in these situations — both Ms. Clapp and Mr. Silverman recommend against putting your device in a bowl of rice. “Rice doesn’t do much in the way of fixing a spill,” Mr. Silverman warns. Instead, “What winds up happening is that you have to do more work in cleaning out rice, which could pop some of the components. It really doesn’t work, and if anything, it could harm the system in the future.”

Take It to a Repair Shop

At this point, you could plug the laptop back in and turn it on. In many cases, it should boot back up again. But Ms. Clapp said you should probably take it to a professional repair shop, just in case.

“Just because something works after you dried it out doesn’t mean it’s fixed,” she said. “Once the fluid intrudes, even after it’s dried, it can leave behind minerals that carry electricity where it doesn’t belong — causing increased corrosion damage over time.” This is especially crucial if you spilled something other than water — like soda or coffee — since those will undoubtedly leave damaging residue behind. A good repair shop will clean the components with powerful solvents or ultrasonic cleaning machines that do a very thorough job.