Every laptop gets warm. Inside a case not much thicker than a magazine there is a processor, a graphics chip, a battery and a charger circuit, all turning electricity into heat while they work. Most of the time the laptop deals with that heat on its own. When it cannot, it slows down, gets noisy, and in the worst cases switches itself off. This guide explains where the heat comes from, how laptops get rid of it, what the laptop makers themselves say about vents and surfaces, and when a cooling pad, a fan or a stand is worth having.
Why laptops get hot
A computer's processor does its work by switching billions of tiny transistors on and off every second, and every switch turns a little electricity into heat. The harder it works, the more heat it makes. Writing an email produces very little; a video call, a game, editing video or a big spreadsheet produces much more. Charging adds heat of its own: Microsoft's support page for its Surface devices notes that extra cooling may be needed until the battery is fully charged.
How a laptop gets rid of heat
Most laptops have one or two small fans. Air is drawn in through vents, usually on the bottom or the sides, passed over metal fins connected to the hot chips, and pushed out of an exhaust vent, often at the back or the side. Dell describes it plainly: fan speed and fan noise rise and fall automatically as the temperature inside changes, and heavy work raises the processor load so the fans run faster and for longer. Apple says the same of its Mac laptops: sensors inside detect temperature changes and the fans come on automatically to cool the parts that need it.
Some laptops have no fan at all. Apple describes its MacBook Air with Apple silicon as having a silent, fanless design: the heat spreads into the metal case and leaves through its surface. A fanless laptop has no vents to block, but it still relies on air reaching the case, and it handles a long, heavy task by slowing itself down rather than spinning up a fan.
What happens when it cannot keep up
A laptop protects itself. When its parts get too hot, it lowers the processor's speed to make less heat, which Lenovo describes as throttling: the laptop feels slow and laggy. If that is not enough, it shuts down to prevent damage. Lenovo calls a loud fan followed by a sudden shutdown a classic sign of overheating. These protections mean a hot laptop is rarely in danger from a single afternoon, but a laptop that runs hot day after day works slower than it should, and heat is hard on batteries. Apple says that using a device where the room is above 35 degrees C can permanently damage battery capacity, and that charging in high temperatures can damage it further.
The room matters too
A laptop can only cool itself with the air around it. Apple asks for Mac laptops to be used where the room is between 10 and 35 degrees C, and warns not to leave one in a parked car, which can get hotter than that. Microsoft notes that above 25 degrees C a Surface's fan may come on more often or spin faster. On a summer afternoon in a conservatory, the same laptop and the same work will run noticeably hotter than in a cool office.
Games, video editing and long jobs
Some work keeps a laptop hot for hours rather than minutes. Games push the processor and the graphics chip hard at the same time, and video editing, exporting and other long jobs keep them busy until the task is done. On these, the fans run constantly and the laptop sits close to the point where it starts slowing itself down. Laptops built for games usually have larger vents at the back and sides for that reason. This is where an open stand or a cooler earns its place, and where a soft surface does the most harm. The accessories for gamers bring the cooling, mice and keyboards for playing on a laptop together.
Vents, surfaces and where you use it
Before buying anything, look at where the air goes in and out. Turn the laptop over and look at the base, then the sides and the back. The intake vents are usually slots or a mesh on the underside; the exhaust is often a grille on the back edge or a side. HP's support pages say the vents on its laptops are usually underneath and on the sides. Every model is different, so look at yours.
Soft surfaces
All the major laptop makers say the same thing about beds, sofas and laps. Apple says to use a Mac laptop on a stable work surface with good ventilation, and not in bed, on a pillow or under bedding. Its page on fan noise adds that soft surfaces such as a sofa, a pillow, a bed or a lap can make the fans run more. Dell says a hard, flat, non-cloth surface lets air reach the fan intake, and that a blanket, pillow, cloth or paper can cover it and cause overheating. HP says a cloth surface such as a lap, a bed or a sofa cushion can restrict or completely block the airflow, and that keeping it blocked for long causes overheating. Lenovo gives the same advice: a flat, hard surface rather than a bed or sofa.
The reason is simple. Fabric and cushions sink around the base and close off the intake vents, so the fan has nothing to draw in. A duvet also holds heat against the case. Working on the sofa for half an hour is not a disaster, but working in bed every evening with the laptop sunk into the covers is exactly what the makers warn against.
Giving it a hard surface anywhere
If you work on the sofa or in bed, the answer is to give the laptop a hard, flat surface to sit on. Lap desks and bed trays do this: a rigid top keeps the laptop off the fabric, and many have a cushion underneath that sits comfortably on your lap. Look for a top that is solid or has holes under the vents, rather than one with a soft cover where the laptop sits.
Other things that block airflow
- Papers and clutter. A laptop sitting on a pile of papers, or with a notebook pushed against the exhaust, is partly blocked. Dell includes paper in its list of things that can cover the intake.
- Cases and skins. A hard-shell case or a skin should leave every vent open. Check the vent cut-outs line up with your model before fitting one.
- Things on the keyboard. Apple says not to put anything on the keyboard of a Mac laptop while it is running, and nothing into the vents.
- Bags. A laptop that is still running, rather than asleep or shut down, can get very warm inside a bag with no air. Check it has gone to sleep before zipping it away.
- Dust. Over months, dust builds up in the vents and on the fan. Dell's first suggestion for an overheating laptop is to clean the vents.
Cleaning the vents
HP's steps are a good general method: turn the laptop off, unplug the charger, find the vents, and blow the dust out of them with canned air. An electric air duster does the same job without buying cans, and the laptop cleaning kits include soft brushes for the grilles. Do it with the laptop off, and do not poke anything into the vents. The guide to cleaning a laptop safely covers the screen, keyboard and ports as well.
Cooling pads and fan coolers
A cooling product adds airflow from outside the laptop. It cannot change how the laptop is built, so it helps most where the laptop's own cooling is struggling: on soft surfaces, in a warm room, or under long, heavy work. Dell describes a cooling pad as having its own fans that supplement the fans in the laptop. Lenovo says pads are especially useful when using a laptop on a soft surface such as a bed or sofa.
Cooling pads
Laptop cooling pads are flat platforms, usually with a mesh top, with one or more fans underneath. The laptop sits on top and the fans blow air up at its base. Most are powered from a USB port on the laptop itself, and some have a spare USB socket so you do not lose a port. Things to look at:
- Size. The pad should be at least as big as the laptop, so the laptop is fully supported and its intake vents sit over the mesh. Pads are sold by the laptop sizes they fit.
- Fan position. One large fan suits a laptop with its intake in the middle; several smaller fans spread the air more widely. If you know where your laptop's intake vents are, choose a pad with fans that sit under them.
- Noise and speed. A pad adds its own fan noise. Many have a speed dial or switch, so you can turn it down for quiet work.
- Angle. Many pads tilt the laptop towards you, which raises the screen a little and sets the keyboard at a slope.
Power and ports
Most cooling pads and stands with fans take their power from a USB port on the laptop, through a short cable. That means they use a little of the laptop's power: on the charger this makes no difference, but on battery the pad's fans draw on the battery too. Many pads have a USB-A plug, so a laptop that only has USB-C sockets needs a USB-C to USB-A adapter or a hub. A pad with a pass-through socket gives the port back for a mouse receiver or a memory stick. Check the cable is long enough to reach the port on the side you need without pulling across the keyboard.
Clip-on fan coolers
Clip-on laptop fan coolers are small units that fit against the laptop's exhaust vent, usually on the side or back edge, and draw the hot air out with a fan of their own. They suit laptops with a clear exhaust grille on the side, which is common on gaming laptops. The fit matters: the cooler's seal has to match the shape and size of your vent, so check the product page against your model. A cooler that does not sit flush can partly block the vent instead of helping it.
Cooling stands with fans
Cooling stands with fans combine the two jobs: they raise the laptop like a stand and blow air at its base. They suit people who want the screen higher and the laptop cooler at the same desk, and who use the laptop with a separate keyboard and mouse. The laptop cooling range has all three kinds together.
When a cooler does little
A cooler works by feeding more air to vents that are there to take it. On a fanless laptop such as a MacBook Air there is no intake to feed, so a pad's fans can only cool the outside of the case. A simple stand that lets air move around the base is often all a fanless laptop needs. A cooler also cannot fix a fan that has failed, vents packed with dust, or a program running out of control in the background, so check those first.
Stands that let air in
A laptop stand is not sold as a cooler, but many of them help. Raising the base off the desk leaves a gap underneath for air to move, instead of the laptop sitting flat with its intake vents pressed close to the wood.
- Foldable aluminium stands hold the laptop on two narrow supports or a frame, so most of the base is open to the air. Aluminium also carries a little heat away from where the laptop touches it.
- Adjustable laptop stands set the height and angle. Check that the platform is open or slotted under the vents rather than a solid plate covering them.
- Vertical laptop stands hold a closed laptop on its edge, beside a monitor. Standing upright leaves both sides of the base open. Before you stand it up, check the vents are not on the edge that sits in the stand.
A stand has another benefit. Raising the screen to eye height, with a separate keyboard and mouse, is what the HSE suggests for anyone using a laptop for long periods, so the same stand can make the desk more comfortable and the laptop cooler at once. The guide to choosing a laptop stand explains the kinds, heights and angles.
Signs it is running too hot
A laptop that feels warm underneath, or whose fan speeds up during a video call, is working normally. These are the signs, drawn from the makers' own support pages, that it is struggling:
- It slows down under load. Programs that were quick become sluggish after a few minutes of hard work, and recover when you stop. Lenovo describes this as throttling.
- The fan runs loudly for long periods on light work. Apple's advice when a Mac laptop runs warm or its fans run for a long time during light tasks is to open Activity Monitor and look for anything using a lot of the processor. On Windows, Task Manager shows the same.
- It freezes, restarts or switches off. Dell lists locking up, not responding, random restarts and unexpected shutdowns as the typical symptoms of overheating.
- The fan makes a new noise. Microsoft says grinding, whining or ticking noises are not normal for a Surface fan. A fan that rattles or scrapes may be failing.
- The case is too hot to rest your hands on. If the palm rest or keyboard is uncomfortable to touch during ordinary work, something is not right.
What to try, in order
- Move the laptop onto a hard, flat surface with nothing around the vents.
- Close programs and browser tabs you are not using, and look in Activity Monitor or Task Manager for anything working hard that should not be.
- Check the power setting. Microsoft says the Recommended power mode on a Surface limits fan speed and runs more quietly than the faster modes, at the cost of some speed.
- Install the system updates. Apple asks for all Mac software updates to be installed, and laptop makers often adjust how the fans behave in updates.
- Clean the vents with the laptop off, as above.
- Add a stand or a cooling pad if the laptop is still hot under the work you need it for.
- If it still shuts down, freezes or makes grinding noises, contact the laptop maker or a repairer. A failing fan is a repair, not something a cooling pad can make up for.
One more note from Apple: temperature apps that show readings from inside the laptop measure the parts, not the outside of the case, which is much cooler, so a high number in an app is not by itself a sign of a fault.
Questions people ask
Is it bad to use a laptop on my lap?
For a short while it is what laptops are for. For long spells, Apple, Dell, HP and Lenovo all advise a hard, flat surface, because soft surfaces block the vents. A lap desk gives you that surface on your lap.
Do cooling pads actually work?
They add airflow to a laptop that draws air in through its base, and help most on soft surfaces, in warm rooms and under long, heavy work. They do much less for a fanless laptop, and nothing for clogged vents or a failed fan.
Why is my laptop hot when I am not doing anything?
Something may be running in the background, such as an update, a backup or a browser tab. Check Activity Monitor on a Mac or Task Manager on Windows. Charging also adds some heat.
Can heat damage my laptop's battery?
Apple says that ambient temperatures above 35 degrees C can permanently reduce battery capacity, and that charging in high temperatures can do more harm. Keep the laptop out of hot cars and direct sun.
Should I worry if my laptop's fan is loud?
A fan that speeds up under heavy work is doing its job. A fan that roars during light work, or makes grinding, whining or ticking noises, is worth looking into.
Will a stand keep my laptop cool?
An open stand lets air reach the base, which often helps. It is not as strong as a fan, but it is silent, needs no power, and raises the screen too.
Where to go next
All the coolers are in laptop cooling: cooling pads, clip-on fan coolers and cooling stands with fans. For the sofa and bed there are lap desks and bed trays, and for clean vents, electric air dusters and keyboard brushes. Delivery is included in every price and tracked to your door.
- How to choose a laptop stand: raising the laptop and letting air underneath
- How to clean a laptop safely: vents, keyboard, screen and ports
- Gaming on a laptop: the cooling, mice and keyboards that help
- Laptop chargers explained: watts, USB-C charging and UK plugs
