PC Overheating Fix: Cool Down a Hot Computer or Laptop
If your PC or laptop is running hot, shut it down, let it cool, then work through four things in order: airflow, dust, background load and fan health. Most overheating comes from blocked vents, dust or a machine working harder than it should. Those are fixable at home in under an hour. If the heat comes back after a clean, the cause is usually inside the case (a failing fan or dried-out thermal paste), and that is a job for a technician.
This guide covers laptops and desktops, what temperatures to worry about, safe cleaning, and the point where you should stop and get help.
TL;DR
Shut down and let the machine cool before you do anything else. Heat is what damages components, not the shutdown.
Check the basics first: vents clear, hard surface or stand underneath, room not too warm, no heavy program running in the background.
Blow dust out of vents with a can of compressed air, with the device off and unplugged, keeping the can upright.
Sustained temperatures around 90°C, repeated shutdowns or a fan that is loud, grinding or silent mean hardware attention.
Thermal paste and fan replacement are internal jobs. Book a technician rather than opening the case if you are unsure.
Table of Contents
What to do in the first minute
When the fan is roaring, the keyboard is hot or the screen has frozen, stop what you are doing.
Save your work if the machine still responds.
Shut down properly. If it is frozen, hold the power button until it switches off.
Unplug the charger and, on a desktop, leave the side panel alone for now.
Move the device to a hard, flat, open surface away from direct sun.
Wait at least 15 to 20 minutes before turning it back on.
Manufacturer support pages, including Dell’s, give the same advice: shut the computer down until it cools rather than pushing on. A hot machine that keeps running can throttle, crash and, over time, wear out the battery and other parts faster.
The common signs are a loud or constantly running fan, sluggish performance, random crashes, and a case or keyboard that is hot to the touch. If you see one or two of these only while gaming or editing video, that may be normal load. If you see them while you are just browsing, something is wrong.
How to tell if it is really overheating
Feeling warm is not the same as overheating. Laptops in particular run warm under load. To know for sure, read the temperature.
Checking the temperature
You can see CPU temperature in the BIOS or UEFI screen (press the manufacturer’s key at startup, usually Del, F2 or F10), or install a free monitoring tool such as HWiNFO or Core Temp. The BIOS reading shows a near-idle figure, so for a true picture, run the monitoring tool while you do the thing that makes the machine hot.
A rough guide from security and hardware vendors, converted to Celsius:
Situation | Typical CPU temperature |
Idle or light use (browsing, email) | Roughly 40°C to 60°C |
Normal load (office work, video calls) | Roughly 45°C to 70°C |
Gaming or heavy rendering | Roughly 70°C to 90°C |
Worth investigating | Sitting at your chip’s limit whenever it’s loaded |
Act now | Shutting down, or throttling at modest temperatures |
The number alone doesn’t tell you much, because the limit differs by chip. AMD’s Ryzen 7000 and 9000 series have a limit of 95°C and are designed to run there under heavy load — AMD describes them as built for a lifetime at that temperature. Intel’s 12th to 14th generation chips sit at 100°C, and the newest at 105°C. That limit is called Tj Max, and reaching it is a safety ceiling, not damage: the chip slows itself down to protect itself.
What actually signals a problem is reaching that limit when you shouldn’t — throttling during light use, temperatures climbing the moment the machine wakes up, or shutdowns under load. Look up your own processor’s Tj Max, then judge against that rather than a general number.
Signs that point to a cooling problem
The fan runs at full speed within a minute of starting up.
Performance falls off sharply after 10 to 20 minutes of use.
The machine shuts down or restarts with no warning, especially under load.
The hot air coming out of the vent is much hotter than it used to be, or there is almost no air at all.
Games or video editing that ran smoothly a year ago now stutter.
Unexpected restarts can also come from power and driver faults, so if heat is not the cause, our guide to what a PC not turning on is telling you and our walkthrough of Windows 11 blue screens help you separate the causes.
Why computers run hot
The causes are fewer than most people expect. ASUS and Dell both list the same handful in their support material:
Dust buildup in vents, fans and heat sinks. This is the most common cause by a distance, particularly in homes with pets, carpet or open windows.
Poor ventilation: a laptop on a bed, couch or lap, or a desktop jammed into a cabinet or against a wall.
A warm room. ASUS advises operating devices in an ambient temperature range of roughly 5°C to 35°C. A Brisbane summer afternoon in a stuffy study with no air conditioning can push a machine toward the top of that range.
High resource use: a runaway program, browser with dozens of tabs, cryptominer malware or a game using everything the machine has.
A worn or failing fan.
Old thermal paste, the compound between the processor and its heat sink.
In Queensland, humidity and heat add to the load, so airflow matters more than it does in a cooler climate. A machine that coped fine in winter can start struggling from October onwards.
Fixes you can do at home, in order
Work through these from easiest to hardest. Stop when the temperature settles.
1. Fix the surface and the room
Put the laptop on a hard, flat surface, or on a stand that lifts the back slightly so air can reach the intake underneath. Soft surfaces such as a doona, couch or your lap block the vents. HP’s support guidance suggests leaving around 15 cm of clear space around each vent. A cooling pad can help a gaming laptop, but it will not fix a clogged fan.
For a desktop, pull the tower a few inches (about 10 cm) from the wall and out of any closed cabinet. Make sure the front intake and rear exhaust are not covered by cables, a rug or a plant.
If the room is hot, run the air conditioner or a fan in the room while you work. Keep the machine out of direct afternoon sun.
2. Close what you do not need
Open Task Manager (Ctrl + Shift + Esc) and sort by CPU. If something unfamiliar is using a large share while you are idle, that is your heat source. Typical culprits:
Browsers with many tabs, particularly with video playing.
Cloud sync tools indexing a big folder.
Windows updates installing in the background.
Malware, such as hidden mining software. If you see a process you do not recognise sitting at high CPU, have it checked. We cover this under virus and malware removal.
Restart the computer to clear anything stuck, then check again.
3. Check power settings, drivers and updates
In Windows, open Settings, then System, then Power, and choose a balanced mode rather than best performance if heat is your problem. Install pending Windows updates, and update your graphics driver and BIOS from the manufacturer’s site. Dell, ASUS and HP all list driver and BIOS updates among their overheating fixes, because fan control is partly handled by firmware.
Many laptops also include a manufacturer app that lets you choose a quiet, balanced or performance profile. ASUS’s Armoury Crate, for example, lets you adjust fan curves, which sets how fast the fan spins at each temperature. If you are not confident changing those, stay on the standard profile. A fan that sounds loud during gaming or video editing is often doing its job, since fan speed rises with CPU and GPU temperature.
If a graphics driver is crashing and spinning the GPU up, see diagnosing graphics driver crashes before you reinstall anything.
4. Clean the vents and fans
This is where most people see the biggest drop. Do it safely:
Shut the device down and unplug it. On a laptop with a removable battery, take it out.
Use a can of compressed air, the kind sold at office supply and electronics stores.
Hold the can upright and a short distance from the vent. Tipping it can spray cold liquid propellant inside.
Use short bursts. Hold the fan blades still with a cotton bud or toothpick so they do not spin up and damage the bearings.
Blow from the exhaust vent in, to push dust back out the way it came, then clean the intake.
Avoid powerful air compressors and household vacuum cleaners. ASUS specifically warns that strong compressed air can damage fan blades, and a standard vacuum can generate static.
On a desktop, take the side panel off, blow out the dust filters, the front fans, the graphics card fans, the heat sink fins on the CPU cooler and the power supply grille. Do this outside or in the garage, not over the carpet.
If the machine is under warranty, check the terms first. Opening a sealed laptop may void it, and manufacturer service may be the better route.
5. Reduce the workload
If heat shows up mainly in games, lower the graphics settings, cap the frame rate, and turn off overlays and background recording. For video editing, lower preview quality. These changes cut heat noticeably with little visible difference.
Laptop or desktop: what differs
Laptop | Desktop | |
Usual cause | Blocked vents and dust in a small heat sink | Dust in filters, poor case airflow, failing fan |
Easy home fix | Hard surface, stand, compressed air at the vents | Clean filters and fans, add or reposition case fans |
What needs a technician | Opening the base, replacing the fan, repasting | Repasting the CPU, replacing the cooler or power supply |
Risk if ignored | Battery wear, throttling, shutdowns | Throttling, instability, shortened component life |
Sustained heat accelerates battery ageing in laptops. If your battery is swelling, draining fast or not charging, read our guides on laptop batteries that will not charge and charging port problems. A swollen battery is a safety issue: stop using the laptop and have it looked at.
Thermal paste: when does it matter?
Thermal paste fills the tiny gaps between the processor and the heat sink so heat moves across. Over years it dries and loses effectiveness. There is no fixed schedule. A typical office PC may go many years without trouble, and a heavily used or overclocked machine may need fresh paste sooner.
Suspect paste if all of these are true:
The vents and fans are clean and spinning properly.
Temperatures climb fast the moment the CPU is loaded.
The computer is several years old.
Repasting means removing the cooler, cleaning the old compound, and fitting it back with the right amount of new paste. On a desktop it is a doable job for an enthusiast. On a laptop it involves opening the machine and often removing the motherboard, so we recommend leaving it to a technician.
When to stop and call a technician
There is a point where more DIY costs you more than it saves. Get professional help if:
Temperatures stay above about 90°C to 95°C even after cleaning and lowering the load.
The fan makes grinding, rattling or clicking noises, or does not spin at all.
The computer throttles or shuts down at normal temperatures.
You smell burning or notice plastic warping near a vent.
Crashes, freezes or blue screens continue after the vents are clear.
You have a sealed laptop and do not want to risk the warranty or the screen cable.
HP Australia’s guidance is that thermal paste failure, a faulty sensor and a dead fan need professional diagnosis or replacement. That matches what we see: once the easy fixes are done, the remaining causes are inside the case.
If you are weighing up whether a repair is worth it, our breakdown of computer repair costs in Australia explains what usually drives the price.
Get it fixed at your home
If you would rather not open the case yourself, we come to you. NextGen IT provides on-site tech support for homes in Brisbane, Logan, Ipswich and Redlands. We assess why your computer is running hot, whether that is dust, a failing fan, paste or a software problem, and explain it in plain English with no jargon. Pricing is fixed after the assessment, and our No Fix, No Fee guarantee means you only pay when the problem is solved.
See our laptop and computer repairs service, or check the page for your area: Brisbane, Ipswich or Redlands. If your machine runs Windows, our Microsoft and Windows support page covers what we handle.
Keeping it cool afterwards
A few habits stop the problem coming back:
Clean on a schedule. Every three to six months for a typical home, more often with pets or a dusty room. A desktop on the floor collects dust faster than one on a desk.
Use a hard surface. Make it a habit with laptops, even on the couch. A tray or board works.
Keep software tidy. Remove programs you do not use and keep startup items short.
Watch the temperature occasionally. If you play games or edit video, keep a monitoring tool open for the first few sessions after a clean to confirm the fix held.
Do not ignore the early signs. A fan that is getting louder each month is telling you something.
Avoid heat when charging. Charge on a hard surface, not under a pillow.
FAQs
Is 90 degrees hot for a CPU?
It depends entirely on your processor. On an AMD Ryzen 7000 or 9000 series chip, 90°C under heavy load is within design spec — their limit is 95°C and they’re built to run there. On an Intel 12th to 14th generation chip, the limit is 100°C, so 90°C is warm but fine. On an older processor, it’s closer to the edge. Look up your chip’s Tj Max, and worry about throttling and shutdowns rather than the number on its own.
Why does my laptop overheat when I play games?
Games push the processor and graphics chip hard, so the fan has to move far more air through a small heat sink. Dust, a soft surface or a warm room will tip it over. Use a hard stand, lower the graphics settings, cap the frame rate and clean the vents.
How often should thermal paste be reapplied?
There is no set interval. Many machines go for years without needing it, while overclocked or heavily used ones may need it sooner. Consider it when the vents and fans are clean but temperatures still spike. Because the job is inside the case, a technician is the safer choice.
Can overheating damage my computer permanently?
Modern processors protect themselves by slowing down or shutting off, so a single hot session rarely causes lasting harm. Repeated or sustained heat, though, speeds up battery wear and can degrade components over time. That is why it pays to fix the cause early.
Is it safe to use a vacuum cleaner to clean my PC?
We advise against it. A standard vacuum can build up static and spin the fans too fast, which can damage them. Use short bursts from a can of compressed air with the device off and unplugged.
Sources
This guide draws on manufacturer support guidance (Dell, ASUS and HP) and our own repair experience. For more on related faults, see our own guides:
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