Abstract: A method of hydraulic fracturing of an oil producing formation includes the provision of a heating apparatus which is transportable and that has a vessel for containing water. The method contemplates heating the water up to a temperature of about 200° F. (93.3° C.). A water stream of cool or cold water is transmitted from a source to a mixer, the cool water stream being at ambient temperature. The mixer has an inlet that receives cool or cold water from the source and an outlet that enables a discharge of a mix of cool or cold water and the hot water. After mixing in the mixer, the water assumes a temperature that is suitable for mixing with chemicals that are used in the fracturing process, such as a temperature of about 40°-120° F.+ (4.4-48.9° C.+). An outlet discharges a mix of the cool and hot water to surge tanks or to mixing tanks. In the mixing tanks, a proppant and an optional selected chemical or chemicals are added to the water which has been warmed.