How do I keep my MacBook Pro from overheating?

Do I need to clean or replace a part?

Perhaps.

A runaway kernel_task can be due to a number of factors, such as:

• a failed or disconnected temperature sensor
• cooling system inefficiency (an inoperative exhaust fan on Macs so equipped, possibly clogged with dust, including the heat sink)
• a worn out, missing, or non-Apple (user-installed) battery on portable Macs
• similar hardware-specific causes including internal hardware additions or modifications, external USB and other connected devices, or the driver software required to use them.

Refer to If kernel_task is using a large percentage of your Mac CPU - Apple Support.

tjk wrote:

I've never heard of the cause/effect working in that direction; it's always the kernel task causing the heat causing the fans....

Apple wrote:

... In other words, kernel_task responds to conditions that cause your CPU to become too hot, even if your Mac doesn't feel hot to you. It does not itself cause those conditions. When the CPU temperature decreases, kernel_task automatically reduces its activity.

Try vacuuming from the outside first. The heatsink fins tend to accumulate a lot of crud. The next most popular cause for cooling inefficiency is debris obstructing the fan impeller's motion. Apple Hardware Test / Apple Diagnostics will readily identify an inoperative fan.

How to use Apple Hardware Test on your Mac - Apple Support

or

How to use Apple Diagnostics on your Mac - Apple Support

If there is dust or other debris I prefer to remove it. A vacuum cleaner is preferable because you know it's gone. Compressed air just moves it around, perhaps making the problem worse, or creating another one in a place that might not be as accessible.

Hi,

I've never heard of the cause/effect working in that direction; it's always the kernel task causing the heat causing the fans....

In addition to John's list of potential "parts," a prime suspect would be the thermal paste between the CPU and GPU (depending on your model), and the heat sink/s.

Had the same issue, (I.E. the running hot part) did two things, I replaced my Hard Drive with a SSD runs faster and cooler than a standard drive. then I built my own Chill mat using two 120 MM 12V fans designed to cool breifcase size electronic cases put these between two thin sheets of plywood put spacers top and bottom now my unit runs more like a refrigerator than a heater mine stays on my desk using a 40" Toshiba as my screen hope this is clear and helps. P.S. these fans draw .5 amp ea. so I broke out one of dozens of power supply's most of us have some used one's laying around put one on that puts out 1.5 amps should last a long time can feel the cool air 3 FT away (yes it's overkill)

Guess I got that backwards! Thanks for the info. 😉