So what should you do if the worst happens?

Don’t panic. By acting promptly, you can usually prevent significant damage. If your laptop is running on battery power and isn’t connected to an AC outlet, quickly press the power button to shut the machine down. Then remove the battery.

If the machine is connected to a power outlet, unplug it. Important: you must do this immediately once the spill has occurred. If the power is removed quickly enough, the electronics inside will be undamaged. Then remove the battery.

Now you aren’t in any immediate danger, so you can start clearing up the mess. Blot up as much liquid as you can with a soft cloth. Next, remove all cables, USB components, cards and any other external devices. Tilt the laptop gently from side to side to drain it, without madly shaking it around, then place it upside down so the liquid can drain out. Removing the outer casing might affect your warranty; if you choose to do so, don’t touch the circuitry inside.

Now all you can do is wait. Leave the laptop open, so air can circulate, for at least 24 hours, in a warm room. You could place it on the sort of rack used for cooling cakes, if you’ve got one.

As long as your laptop hasn’t started to smoke or emit any strange buzzing noises, it should now work normally, but it may look rather smeared and dirty. After all, even before the spill you probably dropped the odd crumb or some cigarette ash on it: all these bits and pieces can adversely affect its performance.

Use a soft, damp cloth to clean the casing – nothing abrasive – or a special cleaning agent, one without any ammonia. Spray this onto the cloth, not directly onto the laptop. Cotton swabs are useful for cleaning around and between the keys.

If you want to clean the display, turn the laptop off first so can see the dirt more clearly. Use a soft cloth to wipe it, never any paper products like tissues, as they can scratch the surface and leave behind lint that can get into the LCD. You can buy special spray solutions for cleaning monitors.