Understanding MacBook Heat Problems - Why is My MacBook Overheating?

MacBooks have a temperature problem that’s been around for years now. Apple tries to make their notebooks thinner and lighter with every generation, but the laws of physics are fighting back with a vengeance. At the same time, the company has to put better-performing components into their machines in order to keep up with user needs. Professional MacBooks are the biggest culprit here. They are commonly used for heavy tasks such as video editing, maxing out the hardware for long sustained amounts of time. That’s a recipe for heat galore, trapped within the tiny confines of a svelte MacBook body.

How Your MacBook Cools Itself

It’s important to understand how your MacBook works to get rid of the heat its components generate. With the exception of the MacBook Air laptops, which have passive cooling, MacBooks use a system of vents, fans, and metal heatsinks. The CPU and GPU push heat into the heatsink. The heat sink then releases that heat into the surrounding air. The fan then moves the hot air out of the machine. This isn’t a special MacBook thing – all laptops with active cooling use this basic approach.

What Happens When Your MacBook Overheats?

When this cooling system can’t cope with the heat anymore, the internal temperature of your components will hit or exceed the maximum temperature they are designed for. What effect this has depends on the component in question.

The effects can be sudden or take a long time to manifest. Damage to your MacBook is possible in some cases, and often your performance will be affected.

For example, the CPU of your MacBook might slow itself down below its normal performance level in order to keep the temperature down – something known as “throttling”. Basically, you won’t be getting the performance you paid for on paper if your MacBook is slowing itself down all the time. This doesn’t mean the CPU is taking serious damage, but constantly hovering around the temperature limit can shorted CPU lifespan in the long term.

If neither the cooling system nor the CPU’s own throttling can keep the temperature below the critical limit, then the CPU and whole computer will suddenly shut itself down. One minute you’ll be using the computer and the next it will simply be dead. This is pretty scary, but it’s actually a good thing since that critical limit is still below the level where serious damage will happen. Your fans will be blasting at full speed and your machine will slow down and feel hot to the touch before this happens, so it’s usually obvious that overheating is behind the sudden death of your session.

There are other long-term effects of high temperatures that may take months or years to manifest. Some of the glues that are used in modern computers may slowly let go under constant heat over time. Likewise, components can creep out of sockets, solder can become brittle and crack, and I’ve even heard stories about screen discoloration from heat exposure.

No matter which way you slice it, too much heat is pretty bad for your MacBook, yet Apple’s design is a recipe for heat issues.

What Can You Do?

There are quite a few things you can do to avoid cooking your shiny MacBook. Some are pretty easy, and some should really only be handled by a professional.

As a regular user, you should first check to see if your air vents are dusty or clogged. A can of compressed air is a good way to blast dust out of the system via the vents. Just make sure you follow the manufacturer’s instructions. For example, don’t tilt the can while using it, since that can cause condensation inside the machine.

The most important thing you can do is ensure that the vents have enough space to work properly – there has to be a supply of fresh air. Don’t put the MacBook down on a blanket and be wary of using it on your lap if your legs or fabric block the cooling system.

If you’re using your MacBook at home, you might consider buying a stand for it so that the bottom of the machine is lifted away from the desk. Heat may become trapped in the tiny gap under the machine and this will help. It’s also good since the metal body of the MacBook itself acts as a heatsink, to some extent.

The ambient temperature of your room also plays a role. On a hot summer day the MacBook has less headroom, so it might hit critical temperatures it wouldn’t have reached in the wintertime. Air conditioning is an obvious fix, but opening a few windows or directing an external fan onto your MacBook might help. I’ve seen people put their laptops on literal bags of ice, but I obviously don’t recommend this radical approach.

Now we get to the stuff only a professional should do. If your overheating issues seem to be more than just the normal MacBook shenanigans, there might be something more serious wrong under the hood.

Have a qualified technician open your MacBook up to check for blockages, dirt, cracked solder, or heat sinks that have come loose.

Keeping it Cool

Ultimately, if you need a computer to do long, sustained bouts of hot work, a MacBook may not be the best machine for the job; a desktop Mac might be a better choice. For high-end uses that come in bursts, or for when you don’t mind slower performance, well, your MacBook is going to be just fine.

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