Fibromyalgia: to investigate the effect of thermotherapy with whole-body cryotherapy in the cryo cabin (temperature - 110 °C) in comparison with mud bath and hot air. Aim of the study was to analyse the parameters: patient's self-assessment, pain intensity (measured with a visual analogue scale VAS) and the number of painful tenderpoints. 66 patients referred to our clinic for rheumatology and rehabilitation, who fulfilled the American College of Rheumatology's criterias for fibromyalgia, were recruited and allocated to one of the two treatment groups. The first group (n = 38) was treated in the cryo cabin (Crio Space Cabin) with -110 °C. The second group (n = 28) was treated in daily turn in a mud bath (mud bath tub Haslauer) and with hot air (BELA Rekord DR 105). The patients were allowed tricyclic antidepressants, analgesics and non-steroidal antiinflammatory drugs as indicated by physicians. All patients were treated with physiotherapy and psychological pain therapy. In both therapy groups, the pain intensity (VAS) could be substantially reduced. The results in the cryotherapy group seemed to be better, but there were no statistically significant effects. There was a great drop-out rate of 20 of the 38 patients (53 %) in the cryotherapy group because of increase of pain intensity, ineffectiveness, panic symptoms and skin lesions. However, the improvement of patient's self assessment in the cryotherapy group was substantially better (72 % versus 29 %). A measurable relief of pain existed for two until three hours after cryotherapy. The data showed no substantial decrease in the number of tenderpoints in both therapy groups. All fibromyalgia patients showed a decrease in pain intensity. Thus, although only 47 % of the patients tolerated the whole-body cryotherapy, the results suggest patients with fibromyalgia should test the cryotherapy in the cryo cabin, if possible. More studies analysing the long-term benefits of the thermotherapy are useful. Moreover, the high number of panic attacks of fibromyalgia patients in the cryo cabin should be investigated in the future.