Neck coolers such as this one have become popular in Japan in recent years, as heat stroke has sadly become a common summer threat while traversing unshaded spaces in the city or in overheated homes.
The neck cooler consists of a collar with two Peltier plaques positioned at the level of the carotids and a rechargeable battery that transmits electricity to the plaques. This technology is the same as that used for small fridges. It is basically a thermoelectric circuit made of two surfaces; one absorbs heat, and the other emits heat. When applied to the neck, this device uses conduction to absorb heat from the body and to move it out in the environment. Cooled blood in the carotid then circulates inside the body to cool down its temperature.
In the speculative article about outer space medicine written by Clynes and Kline in 1959, the two medicine scientists speculate that it doesn’t make sense anymore to envelop the astronaut in a spaceship containing an earthy atmosphere. Instead, we should alter and enhance human physiological properties to adapt them to a new environment. One of their proposals is to develop a state of hibernation and reduce metabolism through appliances that cool down the body. They call this enhanced astronaut, the cyborg. Are we becoming astronauts in our own Earth environment?