Everything you need to know about Macs & Heat

Laptop cooling pads are a cheap and effective way of keeping your Mac cool. The only hitch is that you must be using your laptop on a desk (unless you have a cooling pad thats designed to be used on the lap) to use a cooling pad. And that defeats the purpose of a laptop, doesn't it?

Most laptop cooling pad owners use their laptop on their lap most of the time, and use it on a cooling pad on a desk when they are preforming tasks that makes their computer hot. However some laptop cooling pads are designed to be used on your lap, protecting you from the heat of your Macintosh laptop.

If you don't use your MacBook for intensive tasks, don't go thinking you need a cooling pad, because you don't. You only need one if you preform demanding tasks on your Mac on a regular basis. When your laptop is at 100C you should certainly have it on a cooling pad and not your lap! Another good reason you should have your Mac on a cooling pad when preforming intensive tasks is that it'll chew through the battery fast, and probably will run out of battery life if you don't have it plugged in!

If you have decided that you preform intensive tasks on your Mac laptop and it gets excessively hot as a result, here are a selection of cooling pads I hand picked from amazon. They are quite affordable, ranging from $2 to $35, so have a look!

iStat Pro is another application, similar to SMC Fan Control, that allows you to monitor your Mac's temperature. And although iStat Pro doesn't allow you to change the speed of your Mac's fans, it shows much more detailed heat readings, such as the CPU heat, the hard disk(s) heat, the heat-sink heat and even the heat of your Mac's enclosure!

iStat Pro can be downloaded free of charge here.

In addition to providing temperatures iStat Pro allows you to easily access other information such as how full your hard drive(s) are, your memory & CPU usage, your network usage and your battery health. Some of this information can help in pinning down applications or tasks that can be causing your Mac to heat up.

For many people YouTube is the main source of flash usage, and therefore heat, on their Mac. Up until recently all of YouTube's videos were flash based, however YouTube is now running a HTML5 BETA that anyone can opt into, wether they have a YouTube account or not. HTML5 is a modern alternative to flash, and while not yet developed enough to be able to play all of YouTube's videos, can play a large amount of them. So when you visit YouTube and watch a video, it will play in HTML5 if possible. While HTML5 still uses a significant amount of resources on your Mac, it preforms much more efficiently than Flash, thus reducing heat.

You can opt into the YouTube HTML5 BETA here.

Flash content taxes the CPU of Macintosh computers, heating them up - Click2Flash provides a simple but effective solution: Every piece of flash content is replaced with a button that says "Flash". If you want to view this content, just click the button. However if you don't want to view that particular piece of flash content then Click2Flash will prevent the applet from running, thus saving CPU power.

Click2Flash works in Mac OSX Tiger and later, on the Safari browser. Click2Flash can be downloaded freely from the creator's website.

If you're using Google Chrome there is an extension similar to Click2Flash called "FlashBlock", which can be freely added to your Chrome browser here. There is also a FireFox flash blocking extension that can be found here.

If you notice that your Mac is getting up to temperatures of about 80C (may be less for desktops) for seemingly no reason, it may be because spotlight is indexing. A spotlight index is a task that your Mac preforms from time to time, and occurs especially after you have got a new boot drive, reinstalled or upgraded the OS or have added a large volume of data to your boot disk.

Indexing usually lasts several hours, and is preformed so that your drive can be searched better. Have a look at the spotlight icon (upper right hand corner of the screen). If there is a pulsating dot in the middle of the magnifying glass (as shown in screenshot above) spotlight is indexing on your Mac. Click on the spotlight icon to see how much longer the indexing is going to take. You should avoid performing intensive tasks on your Mac while spotlight is indexing, because performance will suffer and the computer will be prone to overheating. There are no known ways to stop spotlight from indexing.

Note: If you have experiencing abnormal heat after upgrading to Mac OSX Lion, and spotlight is not or has finished indexing, refer to this page.

You may notice that your MacBook heats up when you connect it to an external thunderbolt display (especially the large ones). This is perfectly normal, and is a result of the GPU (graphics processing unit) in your Mac having to drive a much bigger and therefore more graphically intensive display. If you wish to curb this heat you could purchase a laptop cooling pad (see the laptop cooling pad section near the top of this page) and/or use the many other tips detailed here. Please be aware that it does not make a difference if your Mac laptop is open or closed - The computer will be able to vent it's heat just as well if it is closed than if it is open.

It doesn't matter so much on Mac desktops, but the it is easy to cover the laptop's vent(s), especially if you're using the computer on your lap.

On iMacs the vents are located on the bottom of the computer and the upper back of it. There isn't too much you should or could do to free up iMac air vents. One thing you should do however is keep the computer 30cm away from the wall at least. Doing this will stop the same warm air from re-circulating throughout the system.

The air vents on the Mac Mini are located in one place: The back. As with the iMac, keep the machine 30cm from the wall and you should be fine.

On MacBook Pro/Airs, the air vents are all located in-between the screen and the body of the laptop. In the hinge, you could say. The best way to stop your Mac laptop from the overheating is to avoid covering these vents. This is not a problem when you are using the computer on a desk, but if you're using it on your lap you may need to be a bit more careful.

A common myth is that the MacBook family vent heat via the keyboard. This is false. No Mac laptop has ever vented heat through the keyboard. Therefore you are free to purchase and use a keyboard protector without worrying about it interfering with your MacBook's cooling system.