Summary, conclusions and recommendations: adverse temperature levels in the human body

In the spring of 2002, The World Health Organization workshop 'Adverse Temperature Levels in the Human Body' brought together scientists with expertise in biological effects of hyperthermia to review the data and determine the evidence that could be used to evaluate potential adverse effects from human exposures to radiofrequency (RF) electromagnetic radiation in the range of 10-300 GHz. Standards for RF exposure in this frequency range are based currently on thermal effects. Information was reviewed on the ability of hyperthermia, either to the whole body or to part of the body to affect physiology, particularly the heart and circulatory system, to induce other thermoregulatory responses such as sweating, to affect the performance of simple and complex mental tasks, to induce various heat-related disorders such as heat stroke and to damage body tissue. Risks to a variety of organs were considered. In addition, thresholds for effects on developing embryos and foetuses and possible carcinogenic effects were also examined. These findings were discussed in the context of known cellular and biochemical responses of cells and tissues to hyperthermia. The experts judged the relevance of each study for informing decision-makers on the scientific basis for establishing safe exposure levels. The consensus was that standards should consider both temperature and time of exposure, whenever possible.