Abstract: A heat activated dispenser is disclosed which is suitable for dispensing into the ambient a variety of materials including medicaments, insect repellants, odor maskants, and the like. The dispenser is formed from compacted diatomite shaped to fit around and receive heat from a heat source such as a light bulb. The diatomite is charged with a vaporizable material which is released into the ambient in a gaseous state when heat is applied to the dispenser. A method of dispensing a vapor into an ambient comprising providing a volume of material having a vaporizable material therein and applying heat thereby causing said vaporizable material to be dispensed into the ambient atmosphere.