If during the use of your Mac, it suddenly gets hot and the fanes start blowing hard, this means that the processor and the motherboard get too hot. This can occur when you are performing a tough task, for example, rendering a video or another app that requires a lot of processor capacity.
This type of heavy apps are not always the cause, this can also be caused by, for example, a process that lingers in the system itself or, for example, a web page. But also the surface on which you use a MacBook has an influence on the cooling system.
If your MacBook spontaneously starts to blow hard or in the case of the MacBook Air warm and you have not opened intensive apps, there may be something else going on.
Place your MacBook on a flat surface
It is important that the MacBook can store its heat through the ventilation. These are located in the hinge of the screen. Moreover, these are also present on certain models on the left and right side in the rounded angle.
If you block ventilation openings, your Mac can overheat. This is the case when, for example, you use a MacBook in bed on a comforter. It is important to keep the ventilation openings free, use your MacBook on a hard, cool and flat surface.
A laptop position with active cooling
If you use many intensive apps for, for example, video editing app such as Final Cut Pro or 3D apps, it can be useful to use a Laptop position with active cooling.

This is a standard that you can place in different angles and is equipped with fans that cool the underside of your MacBook. Often the fans are equipped with a USB cable for the power supply of the fans present.
Check apps and macOS with activity display
An app or system process can also be the reason that your Mac gets warm. An app that is often the cause of a high load is Google Chrome, especially if you use it with multiple apps at the same time. It is also possible that processes are active in the background that you are not aware of. You can view all processes with the help of the activity display app on your Mac. This app is available as standard under macOS in the MAP utilities.
Open the activity display app and click in the menu bar on ‘CPU’ You now see a tab with the ‘% CPU’ column, which shows which processes cause the most processor tax. Click at the top of the column to sort from high to low, so you can immediately see what the high processor tax causes. Processes that use more than 60% are large consumers.

If you see a process used in the list of a high CPU, you can possibly close it with the cross at the top of the screen (in addition to ‘my processes’). NB! Only do this if you know what you are doing and recognize the app or the system process. If it relates to an app, then it is wiser to de-install and reinstall it.
Check fans with Apple Diagnosis
Of course it is possible that the fans no longer work properly or that there is another hardware problem. You can check this with a special Apple diagnosis app. Every Mac is equipped with this app that can be started with a key combination when starting the Mac. The procedure to perform the diagnosis is different with an Intel and Apple Silicon Mac.

Mac (Apple Silicon)
- Restart your Mac and keep pressing the on/off button while the Mac starts.
- Let go when you see the window with start -up options (toothed symbol).
- Now keeps the command⌘ + D keys pressed.
- Your Mac is automatically restarted and the test is started.
Mac (Intel processor)
- Turn on your Mac and keep the D-Ston pressed.
- Let go when you see the progress bar.
- The test is started automatically.
When performing the diagnosis, the fan is also tested, any abnormalities are reported by the diagnosis app.