Warming up a 2019-era (Intel) MacBook Pro was never my problem. Quite the opposite. Those machines ran notoriously hot. The later macOS releases, combined with company-mandated crapware, made it worse. Doing an ordinary build or starting a videoconferencing session was enough to cause the fans to run. On a warm day the fans couldn’t shed enough heat and so the system would go into thermal throttling. The OS would occupy a core with a 100% kernel_task that didn’t do any work but which would serve to prevent actual work from being scheduled onto that core. When four or five out of the six cores were occupied by kernel_task, I knew I was in for a bag of hurt (to steal a phrase from Steve Jobs). Responsiveness went completely to hell. The machine became effectively unusable.

After a while my normal procedure was to run with the thing sitting on top of an ice pack. That would let me run a 60-90 minute video conference without troubles.

The only redeeming feature of these machines is that they could emulate old x86 hardware at speed. That allowed me to run old apps on old OSes without having to keep old hardware running.

Speaking of cold weather and warming up computers... I've had my fair share of long bicycle commutes during cold winters and I always wondered whether booting up the laptop right after arriving has any effect on the long-term reliability? Like, are there any components which suffer from being activated when they're really cold?

For those without spacebar heating?

"This will start 6 threads that each peg your CPU... "

they're doing what to my CPU????

How big is the risk of condensation when you bring a cold laptop inside?

All their spec sheets say they support up to x% _non-condensing_ humidity, which I’m guessing is about the dew point?

I still use a 2019 MacBook Pro, in 2026 I found the best way to warm it up was to use it daily and not blow the dust out of it for 7 years. After I opened it up and did that it's running a lot cooler.

Does this work with M series ? M series is much colder and my fingers hurt <sob>

Looking forward to the follow up: How to Quickly Cool Down Your MacBook

For years at work I've been just using Cinebench as a hand warmer on various Macbooks.

Multithreaded:

  seq 1 20 | xargs -Iqq -n1 -P0 yes >/dev/null

I just need to build our monorepo

I'm from California... What is this "cold" you speak of?

I think my last Macbook was Wisconsin-locale instead of California. Closing the lid and putting it to sleep actually caused it to heat up (until the battery died).

Alternatively, you could try compiling an Xcode project. That should do the trick as well.

Or you could get a laptop that doesn't have an metal shell, like a thinkpad.

Now do the opposite for the summer! Show me a command line that cools down the machine! ;)

  while true; do openssl speed ecdsap384 -multi 2; done

In homeoffice I always work in the nude and the cold metal of my macbook pro hurts my thighs…

yes only writes y, not the whole word yes

Or something useful, save space, compressing some talk or edu video, just 6 fps is usually enough for slides or code, opus audio can go as low as 32k and still be decent compared to source quality, expect 10-15x size reduction

  ffmpeg -hide_banner -y -i in.mp4 \
    -vf "fps=6,format=yuv420p,scale=960:-2:flags=lanczos" \
    -c:v libx265 -tag:v hvc1 -crf 32 -pix_fmt yuv420p -preset fast \
    -c:a libopus -b:a 82K -application 2048 \
    -c:s mov_text \
    out.mp4

  -x265-params "keyint=800:min-keyint=24:scenecut=20:ref=8:bframes=16:b-adapt=2:rc-lookahead=80:rd=4:subme=5:deblock=1,1:aq-mode=3:aq-strength=0.4:psy-rd=0.4:psy-rdoq=1.0:qcomp=0.7:qg-size=64:rect=1:amp=1:strong-intra-smoothing=1:limit-modes=1:limit-tu=4:rdpenalty=2:tu-intra-depth=4:tu-inter-depth=4:me=star:no-allow-non-conformance=1" \

npm install

Needs 2019 in title, this is Intel MacBooks not Apple Silicon.

Won't work on M processors, (un)fortunately.

Another (more useful) option is to render an animation in Blender, or run a local LLM.

Honestly i prefer my macbook frosty

This is now running Cyberpunk or an LLM locally