Studies on the effects of hyperthermia have aroused great interest in recent years. On the one hand, it has been demonstrated. that hyperthermia may be a useful treatment modality for tumors, in combination with ionizing radia tion or cytotoxic drugs. On the other hand, it is of great scientific interest to study the effects of increased temperature on biological systems. Although hyperthermia has been used in the treatment of cancer for cen turies, its therapeutic success was doubtful. However, since it has been shown that radiation-induced cell killirtg can be remarkably enhanced by...