Heat Diffusers
Heat diffusers use heat to help drops of essential oil evaporate into the air. Heat does tend to change the chemical composition of the oils, so this is not the preferred way to diffuse high quality essential oils. Nevertheless, there are several valuable ways to use heat with essential oils.
For example, essential oils can enhance the benefits of a sauna or steam room. Use only one or two drops at the source of heat or steam, allow the treatment area to heat up, and enjoy air that is completely infused with essential oil during your treatment.
You can also make a steam tent using a bowl, a towel, and a few drops of essential oil. This can be useful as a facial treatment, or as a way to open up sinuses for clearer breathing.