ColdMac 10

If you think it is cold where you live, you might try living in Boston in the dead of winter. To top that, MacFixer (@macfixr or is doing their annual Put the Macintosh out in the cold and see if it survives trick. Only, this is no ordinary trick.

ColdMac 10 is a 2009 iMac 20″ with an Intel Core2Duo 2.66 GHz CPU. Run-ing Mac OS X 10.13.6 (High Sierra), the iMac is decked out with 8gb or RAM, an Nvidia GeForce 9400 and a 500gb HDD, running Apache as a web server.

But before you start sending hate mail, screaming about needlessly destroying a Macintosh, know that this machine lives in a shed at the MacFixer homestead. According to the writeup on the ColdMac10 webpage,

The shed this Mac lives in is very cold. It is not insulated, the door has no seal, and there are two vents in the walls. So while there is a very limited amount of thermal protection, it’s generally within 5 degrees or less of the actual outside temperature at night. During a sunny day, the shed can warm up much warmer than the outside temp. 

This Mac is a 2009 iMac. It is loaded with internal thermal sensors. In addition to that, I use a USB thermometer to get ambient readings inside the shed. In total there are 7 values I picked as the most interesting. They get logged, displayed and graphed. 

The design of the system can be broken down into two halves. A simple script runs every 10 seconds that gets readings from all of the thermal sensors, and loads them into a database. On the other side, this web page pulls that data out of the database and displays it accordingly, showing the current readings, a graph of the last 24 hours, and a graph of the daily high and low for the whole season. There is a lot of javascript that makes the dynamic content happen. But in the end, the database is what makes this possible.

In addition to running all web server related software, this machine plays music on loop 24 hours a day, and runs BOINCscience projects at 50% CPU load.

What is really cool about this page is that the webpage is completely dynamic meaning there is no need to do endless webpage reloads thus reducing the load as well as the wear and tear on the machine further than it already is.

What one deduces from the readings shown on the machine itself, while it might be a typical cold Boston winter, the temperatures shown by the computer itself tells one that inside it is a balmy Hawaii day. But of course, the sub freezing temperatures in the shed or outside will make one think twice about actually going outside to check on it.

The data from the previous winter’s rendition of ColdMac can be found at:

If you want to try out this wonderful look into the Massachussetts winter, go to or follow the project on an annual basis by following the twitter feed for ColdMac at:

Please follow and like us:

About the Author


The A.P.P.L.E. Website is run by the Apple Pugetsound Program Library Exchange Users Group and is open to all Apple and Macintosh fans and their friends.