I ran the first test, this was mostly to verify I could warm the blood bag sufficiently. I have a single layer of water beads with the excess water vacuum pumped out. This impedes heat transfer but maximizes the heat retention of the gel. I did find that the blood would warm to 100 plus degrees in 15 minutes BUT I was concerned about hot spots so I tried swapping the orientation so that the heater is on the outside.

I did an 18 minute video , getting to 100 within 15 minutes was a success but I want the hearing to be more even if possible.