Although whole-body hyperthermia combined with specific genotoxic chemotherapy can be shown to enhance neoplastic cell killing without a concomitant rise in bone marrow toxicity, nephrotoxicity can become treatment-limiting. This study compares the kidney toxicity to the kidney of ifosfamide, carboplatin and etoposide (ICE) chemotherapy alone, and ICE chemotherapy combined with either extracorporeal (e-WBH) or radiant-heat-induced hyperthermia (r-WBH) in 43 patients with refractory sarcoma. Within 3 days of ICE chemotherapy treatment there was a significant increase in urinary protein excretion and a reduction of the glomerular filtration rate. These effects were more pronounced if WBH was added. The use of immunoluminometric assays revealed a predominance of low-molecular-mass proteins. This increase in protein excretion persisted in the e-WBH-treated group, whereas it vanished within 3 weeks in both the group treated with ICE alone and that treated with r-WBH. Our findings suggest that ICE chemotherapy causes transient tubular and glomerular damage, which is enhanced by WBH. In terms of long-term nephrotoxicity e-WBH was more nephrotoxic than r-WBH. This finding is consistent with our clinical observations.