A method of treating disorders in a human or animal subject may include heating a material containing a compound to a first temperature to form a heated volume of the material. The method may additionally include heating the heated volume to a higher second temperature to form a dose of vapor including the compound. The method may also include administering the dose of vapor to the subject to treat disorders such as pain. The method may further include pre-heating the material to a preliminary temperature prior to the heating to the first temperature. The heating and pre-heating may be performed with a capsule including two covering layers, each including an electrically conductive material, configured to hold the material therebetween and to generate heat by resistive heating.