There are plenty of software-based temperature monitoring solutions, fewer hardware-based solutions, and even fewer hardware solutions that include prominent visual indicators. This DIY hack changes the lighting on your case for at-a-glance temperature checking.
Taylor upgraded his hardware and, as a result of the beefier hardware, had a variety of heat-related issues. In order to provide immediate visual feedback on the state of his computer, he cobbled together a temp checking system that toggles an RGB LED behind the front grill of his computer from blue to red based on the internal case temperature.
While we like his initial build, we think that disabling the LEDs in the fan and having the only case light come from a series of LEDs that toggle between blue and red would be an even better way to signal the case temperature–this way the entire lighting scheme would be a unified indicator of the temperature.
Hit up the link below for a parts list, schematics, and code.