#35730 Computer overheating and high fan usage

Hi Peet,

My computer was running really slowly today and the fan was consistenly running. I rebooted twice and closed out of all applications. When I restarted, I checked the Activity Monitor and the Kernel_task %CPU was really high- like in the several hundreds and took a long time to get back into single digits. In looking up what the kernal_task is, it looks like it could be a problem. Let me know if this is of concern or needs any attention.

Thanks,

Julie Lacey

Julie,

Was your fan blowing at full speed, or was the computer silent/quiet? Were all the vents on the bottom and back of the computer clear of obstructions or the computer sitting on anything soft like fabric? ["k](https://support.apple.com/en-us/102172)[ernel_task"](https://support.apple.com/en-us/102172)[will consume as much CPU as possible with a non-cpu-taxing process in an attempt to cool your CPU](https://support.apple.com/en-us/102172). That's the only time "kernel_task" should hit multiple CPU percentages e.g. more than 100% and up to 100% per thread on your cpu e.g. upwards of 1600%.

The only time I've seen this happen was the one time I didn't correctly reconnect a fan on a Mac mini. It was confounding as all get out because that was before that article was published and Apple's last-ditch cooling tactic was common knowledge. I can see that your fan is spinning currently, so I don't think the fan is failed, but the computer may need thermal paste reapplied ... but I've rarely seen that as necessary with macos.

That said, there's an app called "Hot" in "Managed Software Center.app". It's a simple temperature tracking menubar item. Install it, and run it and you'll have a simple view of your CPU temp. I'd recommend turning on "Start at login" in the preferences.

[embedded image]

Researching this more there's a crazy forum post [here](https://www.ifixit.com/Answers/View/556750/kernel_task+takes+up+500%25+of+my+CPU+when+plugging+in+external+monitor), that describes an overheating issue caused by the existence of a "Thunderbolt Bridge" network interface. I call it crazy because the "Thunderbolt Bridge" is a network device on every thunderbolt equipped Mac ... but just incase I believe that I've removed the "Thunderbolt Bridge" interface on your computer. If you look in System Settings - Network, doyou see a "Thunderbolt Bridge" interface like this image:
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[embedded image]

Thanks Peet,

This is how mine looks.

Julie Lacey

From:Artichoke Support - Peet <[email protected]>
Date: Thursday, September 18, 2025 at 1:54 PM
To: Emily Hale <[email protected]>
Cc: Julie Lacey <[email protected]>
Subject: Computer overheating and high fan usage (message id: 99496202)

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Hi Peet,

Yes, the fan runs at full speed when it’s an issue. At my desk it is just on my desk with nothing close to it. When I travel with my computer to and from home, it is in a sleeve and tends to get overheated then as well- even when it is supposed to be shut down or asleep. I will install the Hot app and see what that does.

Thanks,

Julie Lacey

From: Artichoke Support - Peet <[email protected]>
Date: Thursday, September 18, 2025 at 1:49 PM
To: Emily Hale <[email protected]>
Cc: Julie Lacey <[email protected]>
Subject: Computer overheating and high fan usage (message id: 99496202)

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I installed Hot and here is a screenshot of the program

[embedded image]

FYI- as I type this email it is in the 180s and I am not hearing the fan running. The only programs I have running are Outlook, Edge and Teams.

Julie Lacey

From:Julie Lacey <[email protected]>
Date: Thursday, September 18, 2025 at 2:49 PM
To: Artichoke Support - Peet <[email protected]>, Emily Hale <[email protected]>
Subject: Re: Computer overheating and high fan usage (message id: 99496202)

Hi Peet,

Yes, the fan runs at full speed when it’s an issue. At my desk it is just on my desk with nothing close to it. When I travel with my computer to and from home, it is in a sleeve and tends to get overheated then as well- even when it is supposed to be shut down or asleep. I will install the Hot app and see what that does.

Thanks,

Julie Lacey

From:Artichoke Support - Peet <[email protected]>
Date: Thursday, September 18, 2025 at 1:49 PM
To: Emily Hale <[email protected]>
Cc: Julie Lacey <[email protected]>
Subject: Computer overheating and high fan usage (message id: 99496202)

You don't often get email from [email protected].[Learn why this is important](https://aka.ms/LearnAboutSenderIdentification)

Exited to get you a new computer. I'll ping you when the one Grant ordered is ready

Cheers.Peet

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