As spacecraft's size reduces, damage resulting from the effect of thermal fluctuations becomes increasingly detrimental. When components turn on and off, the temperature of the spacecraft interior can rapidly rise, damaging critical components. By including a phase change material that can be integrated into a variety of components, shapes and orientations, the temperature of the spacecraft can be readily regulated. Through such temperature regulations, critical device components will be maintained at optimum operational temperatures. Commercial uses of the proposed ionic liquid heat transfer fluid will include extreme environment vehicles. The performance of these vehicles will be improved by the addition the ionic liquid phase change material that will regulate internal temperatures, reducing energy use within the vehicle. This will, in turn, also reduce the size of heat exchangers leading to more open, workable space within the shelter or vehicle.