You have to carefully look at [upir’s] Arduino thermal camera project because it intersperses pictures of what you expect an 8×8 sensor will produce with images produced by a much better camera.

I used an LCD shield to display the current temperature and speed of the fan, but you can use the circuit without the LCD display. You also need to select the transistor by the type of fan that you ...

Some Python code takes care of converting it into an image. Perhaps you don’t need a camera, but having a way to communicate with an $11 IR temperature sensor might come in handy someday.