All-Seasons Body Cooling/Warming Vest is a special product designed to counter the harmful effects of hot or cold weather stress, lowering or increasing skin temperature, which in turn stabilizes the core body temperature. This allows a person to stay cool or warm and sustain the peak performance levels for much longer.

Current products are based on a cooling method (e.g. evaporative) , or on an warming method (e.g. electric) , not both in the same product.

Novel vest is based on well-known principle of the heat pump which is used for this application: a heat pump works by driving a working fluid or refrigerant around a refrigeration circuit containing four elements, [see Fig.1], (1) evaporator, (2) compressor, (3) condenser, (4) expansion valve. In the evaporator the temperature of the liquid working fluid is kept lower than the temperature of the heat source, causing heat to flow from the heat source to the liquid, and the working fluid evaporates. Vapour from the evaporator is compressed to a higher pressure and temperature. The hot vapour then enters the condenser, where it condenses and give off useful heat. Finally, the high-pressure working fluid is expanded to the evaporator pressure and temperature in the expansion valve. The working fluid is returned to its original state and once again enters the evaporator.

Related to a/m principle description the features of the novel vest include [see Fig.2]:
-Vest back panel composed of three layers: two side layers with plastic tube coil embedded in a fabric, as evaporator and condenser, and one fabric layer in the middle, as thermal insulation.
-Miniature compressor located in a vest pocket, similar to the automatic inflation device operating on batteries or a manual inflation bulb, both used in blood pressure meters.
-Miniature expansion valve, located in a vest pocket.
-Plastic tubes embedded in the vest, as connections between elements.

Vest applications:
• During hot weather period the vest will be dressed with the evaporator side towards the body which is the heat source, vaporization of refrigerant occurs at body temperature, causing skin cooling. The heat is rejected outside by the condenser after vapour compressing.

• During cold weather period the vest will be dressed with the condenser side towards the body. Heat is extracted from ambient air by evaporator, then the compressor pressurizes the refrigerant vapour which flows through the condenser, it loses heat, causing skin warming. Outside air is a common heat source for heat pumps.

Manufacturing of this kind of products consists in usual industrial operations, easy to do, using standard materials and equipment, with lower production cost in comparison with a pair of vests, already in the marketplace, offering separately cold and hot applications each .

All-Seasons Body Cooling/Warming Vest will be useful to the following activities and groups involving millions of people:
• Industry
• Medical community
• Sports
• Families
• Outside jobs
• Outside concerts
• Worshipers standing outside

Estimated costs:
-R&D: $15K
-Marketing: 10$K
-Initial product launch cost: $184.28