raacampbell:
...the LEDs aren't touching the vials and a fan will keep the air flowing, which will stop warm air accumulating around the vials.
But the vials will be absorbing IR, and without removing the heat it'll stay there and not stop increasing. A 'remote thermometer' will tell you the temp of the vials without touching them, but they may need heatsink themselves.
Fascinating experiment. Not he fruit flies, the one being run on the forum. My compliments to your UberController.