Why does my Macbook become extremely hot when using Boot Camp?

The bottom of my Macbook becomes extremely hot when I use Boot Camp (Apple's built-in solution for running Windows on a Mac), especially when I play games. Sometimes my Macbook shuts itself down because it gets far too hot.

Why does this happen, and what can I do to cool it down or keep it from becoming too hot?

The heat is due to heavy CPU usage. Be sure the exhaust vents on the back aren't being blocked by anything -- if the MacBook is sitting on a blanket or your lap, airflow will be reduced and the fans won't be able to cool as well.

My two-year-old white MacBook has never actually shut down due to high heat, but I don't use Boot Camp on it. Perhaps Windows is trying to manage the fan speeds itself and doing a poor job of it? (I'm not sure if Windows even controls fan speeds or if the BIOS does it. Correct me if I'm wrong.)

After almost 8 years of wondering why Mac computers (e.g. 2013 and 2020 Macbook Pro for my part) were overheating so much (reaching 100°C on both models when fully stressed) with Windows (installed with or without bootcamp), I finally discovered why:

My guess is that Mac motherboards do not handle the turbo boost mode of modern CPUs. It is probably handled directly within MacOS, therefore Windows is lost and keeps using 100% of the maximum possible CPU frequencies. But the CPU turbo boost mode should be used only for very short periods of time, not all the time like it does here.

THE FIX: On Windows OS, go to the Advanced Power Options, and then under "Processor Power Managment":

first set "System Cooling Policy" on ACTIVE for both Battery and Plugged in (by default set on PASSIVE on Battery, but it seems wrong except if you lower the "Maximum Processor State" a lot (maybe like 50%).

then set the "Maximum Processor State" at 99% for both Plugged in and Battery (lower on Battery if you want to save it). That's it!

If you open HWMonitor while doing this, you will notice that your CPU frequencies drop directly to the normal frequencies of your CPU (e.g almost always at 3000 MHz before = turbo boost frequencies, and at 1995 MHz after the fix). If you go lower than 99% you will notice that the frequencies change with normal ratios.

The downside of this is that we loose the turbo boost option of our CPUs, but in my opinion it is better than having the fans always running at their maximum, and damaging your hardware (CPU, but also the motherboard itself when it reachs 100°C!)

Cheers!

I would recommend downloading smcfancontrol and turning the fans on to max so that it doesnt get too hot.

When you reboot into windows it will remember your fan speed setting until you turn your machine off.