Among the different methods of whole-body hyperthermia (WBH), the energy transfer with infrared radiation seems to have established itself as a relatively simple procedure. The infrared systems differ with regard to the used spectrum of radiation. In the case of water-filtered infrared radiation, infrared A (760-1400nm) is the focal point of heat radiation. This radiation penetrates deep into the skin up to the capillary area of the corium. Eighty treatments of patients in an advanced stage of cancer (40 male, 40 female, April 1998-April 1999) were performed with a WBH device with water-filtered infrared radiation, IRATHERM 2000. Extreme WBH was combined with induced hyperglycaemia and relative hyperoxaemia, and for 83% of the patients with chemotherapy as well. The body-core temperature was measured rectally (85%) or vesically. The objectives of the thermal control were a low rate of side-effects and a quick rise of the body-core temperature with regard to the condition of the patient's skin. The mean duration of the rising phase (37.5-41.5°C) was 87 ± 19min. A correlation between lamp power and rising time (r = 0.08) was not found. Moreover, no correlation could be found between the appearance of thermal lesions WHO 2nd degree and the lamp power. Thermal lesions according to WHO 1st, 2nd and 3rd degrees appeared in the case of 20, 15 and one treatment, respectively. Their area amounted in 2nd-degree cases to 0.08% of the body surface, on average. The highest mean temperature over 60min (T[sub 60]) was 42.1 ± 0.1°C, and the mean of maximum temperature (T[sub max]) was 42.3 ± 0.1°C. The mean thermal isoeffect dose EM[sub 43] was 35.8 ± 6.3min. WBH with water-filtered infrared radiation in combination with induced hyperglycaemia and relative hyperoxaemia (procedure of systemic Cancer Multistep Therapy) is a safe and practicable procedure with good tolerability in the case of experienced application. It permits a rapid rise of body-core temperature and a high thermal constancy in the plateau phase. An all-around access to the patient is possible in all therapy phases. [ABSTRACT FROM AUTHOR]