Pelvic perineal recurrence rate is the major therapeutic problem after curative surgery of extraperithoneal rectal cancer, after lower anterior resection as well as abdomino-perineal resection: local failure rate is high, particularly for stages B2-C. Radiotherapy alone or in combination with chemotherapy proved to be an useful adjunct to surgery. Postoperative radiotherapy, with 40 to 50 Gy doses, has shown local improvement, but causing intestinal damaging. There is now evidence that hyperthermia enthances radiation effects, by killing radioresistant acid tumor cells. In order to give high postoperative radiation doses, without intestinal damage, and to kill acid tumor cells by hyperthermia, we developed a device, able both to displace intestinal loops and to produce combined hyperthermia. From 1993 to 1995, four patients with Astler-Coller stages B2 (2 patients), C1 (1 patient) and C2 (1 patient) distal cancer, were operated by Hartmann's procedure and treated with postoperative radio-hyperthermia with our device. Overall radiation dose delivered in the pelvic area was of 65 Gy, associated with three heating sessions at 43 degrees C for 30 minutes. Pelvic infection occurred in one patient; all pelvic byopsies were negative and no bowel damage was found. Three patients underwent recanalization, one had anasthomotic leackage. The C1 and C2 stage patients died from hepatic metastasis, 18 and 11 months after recanalization; one B2 stage patient is still under treatment and the other is alive and disease free 13 months after recanalization. Our technique allows to give high postoperative radiation doses, without small intestine damage, and to give a good hyperthermia for better control of local failure.