Thermal therapy apparatus for a patient, comprising: a flexible base for conforming to the patient; a plurality of reaction compartments, each compartment containing a first of at least two thermal reaction components, the thermal reaction compartments being interconnected by fluid conduits, each reaction compartment being in thermal contact with a heat transfer surface, wherein the heat transfer surface is a cooling surface, for contacting a surface portion of the patient which will transfer heat to the patient, the thermal reaction components having an initial state where the thermal reaction components are separated from contact with each other, and a treatment state in which the thermal reaction components are placed into contact, wherein a thermal reaction takes place and transfers heat with the cooling surface and the corresponding portion of the patient; a liquid chamber comprising a flexible wall and containing a second of the at least two thermal reaction components, the second thermal reaction component being a liquid, the liquid chamber being connected to the fluid conduits by a valve; characterized in that it further comprises: a gas chamber adjoining the liquid chamber; a gas container having therein a pressurized gas, and a fluid connection between the gas container and the gas chamber, and a gas valve for selectively releasing the pressurized gas from the gas container through the fluid connection into the gas chamber; wherein upon operation of the gas valve, pressurized gas will flow into the gas chamber and the gas in the gas chamber will apply pressure to the liquid chamber and force the second thermal reaction component through the valve and into the fluid conduits and thereby into the thermal reaction compartments, where the at least two thermal reaction components will react and transfer heat with the heat transfer surface, and the presence of the gas within the gas chamber will support and cushion the patient. a flexible base for conforming to the patient; a plurality of reaction compartments, each compartment containing a first of at least two thermal reaction components, the thermal reaction compartments being interconnected by fluid conduits, each reaction compartment being in thermal contact with a heat transfer surface, wherein the heat transfer surface is a cooling surface, for contacting a surface portion of the patient which will transfer heat to the patient, the thermal reaction components having an initial state where the thermal reaction components are separated from contact with each other, and a treatment state in which the thermal reaction components are placed into contact, wherein a thermal reaction takes place and transfers heat with the cooling surface and the corresponding portion of the patient; a liquid chamber comprising a flexible wall and containing a second of the at least two thermal reaction components, the second thermal reaction component being a liquid, the liquid chamber being connected to the fluid conduits by a valve; characterized in that it further comprises: a gas chamber adjoining the liquid chamber; a gas container having therein a pressurized gas, and a fluid connection between the gas container and the gas chamber, and a gas valve for selectively releasing the pressurized gas from the gas container through the fluid connection into the gas chamber; wherein upon operation of the gas valve, pressurized gas will flow into the gas chamber and the gas in the gas chamber will apply pressure to the liquid chamber and force the second thermal reaction component through the valve and into the fluid conduits and thereby into the thermal reaction compartments, where the at least two thermal reaction components will react and transfer heat with the heat transfer surface, and the presence of the gas within the gas chamber will support and cushion the patient.