MLX90640 out-of-box glitch, help!

Greetings. First post.
Just received my MLX90640 breakout from Mouser. First Pimoroni purchase. I attached the pins and ran the Sparkfun sketches on an Adafruit Feather M0 wired to my Win7 laptop. I had to edit some incompatibilities, but it ran pretty well… except for this.


These are three screen grabs: my blank ceiling, my right palm (okay, mirrored image…good to know), and my thermal webcam selfie. Counting from top left, every 82nd pixel is 20-30 degrees hotter than its neighbors. Nothing in the field of view is really radiating 58 degrees. Can anyone enlighten me why my new thermal eye is behaving this way? Everything else about it seems ideal. Thanks in advance.

(I’m allowed only two links? I hope that limit expires quickly.)

Hallelujah!
Disciple

Nearly a week and no replies. Here’s my update.
On Thursday I had access to a Pi 3, so I followed the product link to the Github.com page and opened the readme. There I was utterly and soundly defeated. Hours wasted googling opaque and incomprehensible instructions, I got as far as make clean before becoming completely mired. Are there no instructions for beginners like me who don’t already know all the Linux code words and secret handshakes?
One voice on Discord suspected that the original sketch created the glitch due to a programming bug, so that will be my line of investigation. I just wish the takeoff curve here at Pimoroni wasn’t quite so steep for a non-expert such as myself.

Hallelujah!
Disciple