A method and kit of components for destroying organisms and toxins in from an enclosure such as a building. Temperature sensing probes are installed in the enclosure to indicate structure temperature and a recorder is used to record the temperature of said sensing probes in real time. Hot air is introduced into the enclosure through one or more ducts to raise the structure temperature to at least about 120° F., as monitored by the temperature sensing probes. This is sufficient to kill essentially all insects, bacteria, virus, dust mites, spiders, silver fish, fungi and toxic molds such as aspergillus oryzae, aspergillus terreus, aspergills versicolor, cladosporium hergbarum, stachybotrys chartarum, penicillium aurantiogriseum, pencillium chrsogenum, pencillium glabrum and fusarium oxysporum. and the like. The air can exit through open doors and windows or through ducts to a filter assembly that captures the remains of the organisms. Ozone may be added to the heated air to improve efficiency. Preferably, air when extracted from an egress duct downstream of the filters improves air flow through the enclosure and filters. A typical building can be treated in six to eight hours.