feet can get really warm so why not treat them with some kinda fan cooling to lessen your AC bill.
these pumps take less than 3 watts or less to pump and with adjustable power supply you can run them on 1.5 – 2 volts
stainless would be a better choice. also dont forget to solder both layers together if using copper 2 layer pcb.. tape one side because copper can be poisonous. also use ice for the intake air if needed. i noticed mine was getting hotter at times with the temp gun so i added water cooling.
another idea for these is just to use the pump and tubing without the heatsink and make a personal water cooled jacket. one of those phone battery packs would run this setup for a good 8 hours probably. just need to change water or add ice to resivoir when high temp alarm hits. also if its too cold you can put a thermistor on it and use an arduino to turn on and off the pump to prevent what i call radiant cooling that can make you sick. put a layer of insulation between you and the tubing like a vest to reduce cold shock temps
https://www.youtube.com/watch?v=6YTdSWItWsk
