Running an electric cooler creates heat, the weight of the batteries to run an electric cooler means the wearer would need to do "more work" which creates even more heat, batteries generate heat when used, solar panels soak up heat from sunlight, etc. So after a short amount of use the wearer would be generating more heat than the device could cool off. Perfect, "3~5 years away", vaporware.
Too useful
Very useful, but impossible.
Running an electric cooler creates heat, the weight of the batteries to run an electric cooler means the wearer would need to do "more work" which creates even more heat, batteries generate heat when used, solar panels soak up heat from sunlight, etc. So after a short amount of use the wearer would be generating more heat than the device could cool off. Perfect, "3~5 years away", vaporware.