Fluid system and method of making and using the same

A method comprising:

• providing a product including a housing, comprising at least one phase change material and a medium, wherein the housing is constructed and arranged for thermal energy transfer to or from a vehicle fuel wherein the medium comprises a layer in contact with or adjacent to a flow or static state of the fuel;
• providing a vehicle comprising a container comprising vehicle fuel;
• placing the product so that the medium is in contact with or adjacent to the container of vehicle fuel or the fuel itself;
• transferring heat to the fuel from the phase change material or transferring heat from the fuel to the phase change material wherein the phase change material does not include an icosane or decane and wherein the phase change material is encapsulated by a polymer comprising polyuria-formaldehyde.