An apparatus for portable delivery of nitric oxide without the need for pressurized tanks, power supplies, or other devices provides a single therapy session by triggering a heater to heat a reaction chamber. A piercing assembly may trigger to open sealed containers, such as bags, of liquid water or salt water in order to activate the heaters. Upon addition of liquid such as water or salt water to a chemically reactive heating element, heat is generated to activate the chemicals generating nitric oxide within a sealed reactor. Upon triggering, liquid containers are unsealed, the liquid drains down to initiate reaction of the heating chemicals, and the heat begins to penetrate the reactor. The reactor, in turn, heats its contents, which react to form nitric oxide expelled by the reactor to a line feeding a cannula for therapy.