A laptop on fire, engulfed in flames.
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If your computer is going up in flames, it's usually best to evacuate and call the fire department. If you know what you're doing, you could use the right fire extinguisher to quell the blaze, but it's best to prevent fires in the first place.

No one starts their day expecting to see literal flames from their computer, but it happens more often than you think! If you never want a PC fire, or want to know what to do if it happens, take notes.

Warning: If you’re reading this because your computer is on fire right now, evacuate immediately. Activate any nearby fire alarms and contact emergency services.

Why Would a Computer Catch Fire?

There’s a ton of energy going into and coming out of the typical PC these days. If the flow of power is derailed for some reason, the heat can lead to a PC barbecue in no time flat! A PC that’s not properly ventilated or running too demanding tasks for its cooling system can generate a lot of heat, which can cause internal components to overheat and potentially catch fire.

If a computer is connected to a power source that experiences a sudden surge or spike in voltage. In that case, this can cause the computer’s internal components to become damaged and potentially catch fire. Defective components, such as a faulty power supply or motherboard, can also cause result in ignition.

Good old user error is another common culprit. If a computer is mishandled or misused by the user, such as by opening the case and touching the internal components without proper training or knowledge. In that case, this can damage components and potentially cause a fire.

Fires can also happen when electrical connectors are not correctly seated. According to NVIDIA, this is one of the potential reasons that some RTX 4090 graphics cards have exhibited melting cables and the potential for a fire hazard.

Some components, especially power adapter cables and plugs, may not have sufficient capacity to carry the current coursing through them. This leads to hot spots, melting, and potential ignition.

Short circuits can also cause fires. A short circuit happens when there is an unintended connection between two points in an electrical circuit, which can cause a sudden and uncontrolled flow of electricity. This can overheat electrical components and potentially cause a fire.

Various factors, such as damaged or frayed cables, faulty components, or incorrect wiring, can cause short circuits. Some of the other causes mentioned above may have had a short circuit as their starting point.

What to Do When a Computer Catches Fire

The main recommendation if there’s a computer fire is to evacuate, alert other people using a fire alarm or other appropriate methods, and call emergency services.

If you are trained, and it is safe to do so, you can use a fire extinguisher to try and put out the fire. However, you must exercise good judgment as to whether the fire can be dealt with in this way. If you have any doubts at all about whether the fire can be controlled and put out with an extinguisher, you should evacuate the area and call the fire department.

If at all possible to do safely, cut off the electricity supply to the computer since the continued power flow may worsen the fire. If you can’t do this, don’t worry and just evacuate to safety, in most cases the circuit breaker should cut the power if something goes wrong in the electrical circuit.

Choosing the Right Fire Extinguisher

The correct fire extinguisher type to put out a computer fire is a Class C fire extinguisher. Class C fire extinguishers are designed for fires involving electrical equipment, such as computers, and are safe to use on electrical fires without causing further damage. Class C fire extinguishers use a non-conductive extinguishing agent, such as carbon dioxide (CO2), to quickly and effectively extinguish the fire without conducting electricity and causing further damage.

Kidde Pro 210 Class ABC Fire Extinguisher

A product everyone should have but hope to never use. This Class ABC home fire extinguisher won't take up much space, and you don't need a rocket scientist to operate it. Keep it in your computer room just in case.

It is important to avoid using a water-based fire extinguisher on a computer fire. Water-based fire extinguishers can conduct electricity and cause further damage to the computer, making the fire worse and potentially causing injury. The only situation where such an extinguisher is suitable is if the electricity supply has been turned off and you’re not concerned about further damage to the computer.

If you are unsure which fire extinguisher to use on a computer fire, it is best to contact the fire department and let them handle the fire. The fire department will have the appropriate equipment and training to safely and effectively extinguish the fire without causing further damage or injury.

Handling Computer Fires Involving Lithium Batteries

You’ve probably read many stories about fires involving lithium-ion batteries in devices like smartphones and laptops, and this is one of the biggest fire hazards in any computer that uses this technology. It’s one of the main reasons airlines limit the battery size that’s allowed on a plane.

Despite how violent and dangerous lithium battery fires can be, they are also quite rare. Modern batteries are packed with numerous safety features to prevent fires, and new lithium battery technologies are developing to make them much safer. Still, when a battery does go wrong, it can be quite scary!

Although they’re called “lithium” batteries, which might suggest a Class D fire extinguisher for burning metals would be the right choice, lithium batteries are actually a Class B fire. So the typical Class ABC multipurpose fire extinguisher should be suitable. They are classified this way because of the liquid electrolyte in the battery.

Preventing Computer Fires

Let’s be honest, once your computer is actually on fire, most people shouldn’t do anything more than heading for the nearest exit. The most important thing you can do is prevent fires from happening in the first place. To paraphrase a certain famous fire safety mascot: Only you can prevent computer fires! To that end here are a few good general tips.

Keep your computer clean and dust-free. Dust can accumulate inside your computer and block the vents, which can cause the internal components to overheat and potentially catch fire. To prevent this, regularly clean the inside of your computer and the intake and exhaust vents, which may have removable dust filters.

Keep your computer well-ventilated! Proper ventilation is crucial for preventing your computer from overheating and catching fire. Ensure that your computer has plenty of airflow around it, and avoid blocking the vents or placing it on a soft surface that can block them.

Use a surge protector. Power surges can cause damage to your computer and potentially cause it to catch fire. To prevent this, use a surge protector to protect your computer from sudden spikes in voltage. Even if you aren’t particularly concerned about computer fires, using a surge protector is a good idea for any sensitive electronics.

Only use quality cabling and components! Avoid no-name computer parts if possible since these are most likely to play fast and loose with safety standards.

Avoid opening your computer unless you know what you’re doing. Touching the internal components without proper knowledge can cause damage and cause your computer to catch fire. For example, you may accidentally create a short circuit with a screwdriver or puncture your laptop battery by accident if a tool slips. There’s nothing wrong with working on your own computer, but do a little research beforehand rather than going in blind.

Fire Bad!

Until this moment, you may have never even considered the possibility that the computer on your desk (or lap!) might spontaneously combust, but it’s more than a theoretical possibility. This author has experienced two small computer fires involving cheap power cable adapters melting and igniting surrounding plastics and other materials.

Thankfully in both cases, someone was there to notice the smoke and small flames, confining the fire to the computer itself. But it if had happened overnight or while no one was around, these small accidents could have been much worse. Prevention is key!

RELATED: 7 Tips to Keep Your Tech From Overheating

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Sydney Butler has over 20 years of experience as a freelance PC technician and system builder. He's worked for more than a decade in user education and spends his time explaining technology to professional, educational, and mainstream audiences. His interests include VR, PC, Mac, gaming, 3D printing, consumer electronics, the web, and privacy. He holds a Master of Arts degree in Research Psychology with a focus on Cyberpsychology in particular.
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