The Reon Pocket is a fairly slim palm-sized white plastic device that charges over USB-C and connects to your iOS or Android phone with Bluetooth. It definitely looks like a Sony gadget. There’s a silicone pad on the back that you can press against your skin, and the Reon Pocket uses the Peltier effect to cool or warm itself up by absorbing and releasing heat. You can use it handheld, but the most widely promoted use cases involves buying Sony’s special V-neck undershirts with a pocket on the inner back to keep the device resting between your shoulder blades… More here.
I love this idea, particularly as someone who loves hot weather, but also suffers in it.