The temperature of an object is a measure of the average kinetic energy of its molecules. In a hotter substance, the molecules are vibrating, rotating, and translating more rapidly than in a colder substance.

Heat may be transferred anytime two objects of different temperatures come in contact. On the interface, faster molecules collide with slower molecules. When collisions are between particles of very similar masses, a collision between a fast and slow object will result in both objects moving with speeds somewhere in between the initial extremes. Think about billiard balls. A fast ball hitting a slow ball will cause the second ball to move, but not as fast as the first; and the first to slow down a little.

In a typical climate-controlled environment, like a home with a thermostat, all inanimate objects will tend to assume room temperature by being in contact with the ambient air over time. A thermometer placed on any two objects will show they have the same temperature in the morning.

But objects feel different to the touch. A steel pipe can feel cold, and a fuzzy blanket can feel warm when they are the same temperature. Steel wool can feel warm and fuzzy after it has been sitting in the same room as a steel pipe.

This is because human beings have their own thermostats that keep their bodies at 98.6°F. When they touch objects that are 70°F, heat is transferred from the hotter body to the cooler object. If an object is a good conductor, its molecules are free to accept the heat from the human and pass it on, via collisions, to neighboring molecules. Surface molecules can thus continue to accept heat for a long time before neighboring molecules run out of cooler places to put it, and the material heats up to 98.6°F. Water, like metals, is a good conductor.

When metal is fuzzed into steel wool, it breaks up conductive paths and traps a lot of air. Trapped air is a good insulator. Because the molecules in insulators are not good at transferring heat, they heat up to 98.6°F rapidly and no further heat exchange occurs.

The warmth of foam to the touch will largely depend upon how much water (or moisture) it contains, how much air or other insulating materials it contains, and the length and overall volume of conducting paths.

Good electrical conductors are good thermal conductors. An analogy to circuit electricity can therefore be drawn. The current (number of electrons flowing through a given cross-section in a given amount of time) can be increased by increasing the electric potential, widening the wires, adding more wires in parallel paths, increasing the conductivity of the wires, etc.

With foam, conductivity can be increased by increasing the temperature differential to the surface, closing up the cell structure to create more and longer conductive paths, decreasing the amount of trapped air, or even changing the chemistry to use more conductive materials.

One reason Gel-Viscoe feels so cool is that it is a gel-like material. The lack of rigidity with which the molecules are held in place with respect to each other helps to conduct heat from the skin through the foam and out the other side.

N.J. Mills at the University of Birmingham, UK, compared the cell structure of Gel-Viscoe to other foams. Gel-Viscoe is considerably denser (220kg/m3) than 2nd Generation Viscoe (80kg/m3) and other foams. Microscopic observations of 2nd Generation Viscoe and Gel-Viscoe indicate that Gel-Viscoe cells (air pockets) are round, whereas 2nd Generation cells are compressed into each other, occupying space that would be filled by polyol in Gel-Viscoe. A high density means there is less trapped air in the material, and more cross-sectional area for heated molecules to transfer any additional kinetic energy to a greater number of molecules.

Gel-Viscoe has other features that migrate its ability to conduct heat. Its cells (polyol membranes surrounding air bubbles) are the same size as those of other foams, but the holes in them tend to be larger. This should help air to flow, making Gel-Viscoe a poor insulator, except that other factors like the size and alignment of the holes combine to make Gel-Viscoe 2-3 times less permeable to air than other foams. However, since the amount of air trapped is small compared to the volume of conducting paths available for molecular collisions, Gel-Viscoe will wick away heat from the skin and feel cool