A radiant therapeutic heating apparatus may include a radiant heat generating layer having a plane surface including an infrared radiator adapted to radiate heat evenly from its surface, a pair of flexible electrically insulating and radiation-permeable layers located adjacent and covering opposite sides of the layer, a thermal insulation layer disposed against and covering one of the electrically insulating layers, and a sealed radiation permeable envelope enclosing the heating apparatus. The flexible heat generating layer may include a fiberglass material impregnated with a resistive material, which material may provide a surface temperature, when current is conducted therethrough, of no greater than about 54 degrees Celsius. Current limiting thermostats may be provided to prevent energy and temperature spikes. A stiffening element may help protect the components, and may orient portions of a user's body (such as, e.g., but not limited to, the wrist for repetitive strain injuries) in a therapeutic position. The heating apparatus may be used on animals such as, e.g., but not limited to, mammals, including pets, humans, horses and/or other living beings and/or creatures. The apparatus may be oriented as a blanket, and may incorporate, e.g., a rheostat, high-low, analog, digital, or other power control switch. It may be used for warming kennels, for treating hypothermia, for relieving neck, shoulder and/or back pain. It may be used for pre- post- and during, operative care. It may be combined with other therapy such as, e.g., massage and/or vibration.