So, what is a PolarSkin Ice Sheet? Why?
Let us start with the intended use of PolarSkin Ice Sheets (PSIS). PSIS are used to quickly cool off a person that is overheated. The objective is to reduce and/or stabilize a person’s body temperature experiencing a heat related injury. Pretty simple.
A PolarSkin Ice Sheet is engineered to accomplish a single task. The task is to rapidly transfer (off-load) thermal energy/heat from a human being to a receiving material void of thermal energy. Simply taking something that is hot and sticking it to something cold and waiting until they both are the same temperature. Rinse and repeat.
Thermal transfer or "cooling" can only take place by conductive, convective, or evaporative methods. PolarSkin Engineers built all three modes into a single product. PolarSkin Ice Sheets. PSIS wets the skin promoting evaporation; places a film of "ice" over the torso, axilla, and pelvic area that promotes conduction; the material allows and promotes air for convection.
Any item, thing, critter, or human has mass. More in some cases and less in other cases but mass none the less. Because they have mass, they also have surface area. A limited and defined amount of surface area. Homo Sapiens are no exception. However, not all surface areas equal.
Humans are in large part made of water. This water is found in blood and tissues. Muscles are large, geometrically defined blobs of tissue and blood. Water is dense and has high potential energy. Thus, when a person becomes overheated, the water in their body is too hot. Plus, there is this throbbing pump in the body pushing the hot water all around the body causing mischief.
Thermal energy or "heat" is trapped in a human's body. To escape the heat can only egress and ingress via the surface area of skin. Locations with heat massed and trapped is ideal real-estate. Waterfront living.
Location, location, location. The valuable surface area for overall temperature reduction is located near large and moderately viscous masses of muscle. The human torso, axilla, and pelvic region contain valuable real-estate for thermal exchange.
PolarSkin Ice Sheets interface directly with human skin. The interface is wet and tacky gel. The gel is called ArcticAqua. ArcticAqua is a shelf stable, benign, phase change material. The material experiences four unique and distinct phase changes while absorbing thermal energy. These phenomena allow the material to absorb significantly more thermal energy than is obtainable by sensible thermal exchange.
ArcticAqua is carried on a PolarSkin Mini-Mesh substrate. The substrate is woven, finished, and geometrically shaped capture and hold high volumes of gel relative to the material substrate. The substrate contains minute holes in the weave that expand and contract with physical movement, the application of thermal energy, and via the flow of ArcticAqua in and around the substrate.
The substrate and gel are mechanically compressed to form a PolarSkin Ice Sheet. The Ice Sheet has the consistency of a flexible gelatin. It flows and physically conforms to the human form ensuring maximum surface area contact and/or wasted cooling capacity of the product.
Cold PolarSkin Ice Sheets cover large amounts of human skin surface area with emphasis place on the most valuable real-estate containing dense muscles and blood flow. The PolarSkin Ice Sheet with ArcticAqua adhere to skin. The temperature differential between the human skin and the Ice Sheet creates a significant Δт. The wide Delta T encourages thermal exchange allows the Ice Sheet to rapidly transfer thermal heat from the human skin to the Ice Sheet.
If properly place, the PolarSkin Ice Sheet with quickly absorb the bodies thermal energy and become warm. Rinse and repeat.