According to the Dachau Comprehensive Report, anesthesia and bath temperatures ranging from 2 to 12°C had no demonstrable effect on the rate of cooling. These surprising observations are at variance with generally accepted concepts and raise strong doubts about the experimental approach. For example, Keatinge noted that immersion in water at 5°C is tolerated by clothed men for 40 to 60 minutes, whereas raising the water temperature to 15°C increases the period of tolerance to four to five hours.20 Moreover, the report contains no specific information about the effects of age, clothed as compared with unclothed immersion, or nutritional state on the rate of body cooling.

Cardiac arrhythmias are described in the Dachau Comprehensive Report as being slow, fast, or irregular, without reference to standard nomenclature. Ventricular fibrillation, known to be a common cause of death from hypothermia, and atrial fibrillation, the most frequent cardiac irregularity from hypothermia, are not even mentioned. The term atrial flutter, the only conventional designation mentioned, is used to label a tracing of atrial fibrillation. The unusual characterization of common cardiac arrhythmias and their misinterpretation suggest a lack of expertise in cardiac physiology.

According to the Dachau Comprehensive Report, the subjects' body temperatures continued to fall after they were removed from the cold bath, and it was postulated that this "after drop" might be responsible for death after rescue from cold water. The temperature curves in the Dachau Comprehensive Report, however, show the presence of the "after drop" to be variable.

The data for one of the more crucial aspects of the project, the assessment of the lethal temperature level, are incomplete and inconsistent. An assistant testified that the victims were cooled to 25°C.14 In a short Intermediate Report, Rascher noted that all those whose temperatures reached 28°C (an undisclosed number) died.21 However, the postscript to the Dachau Comprehensive Report maintains that "with few exceptions" the lethal temperature was 26 to 27°C. In a further inconsistency, the Dachau Comprehensive Report notes that in six fatal experiments the terminal temperature ranged between 24.2 and 25.7°C. Even more puzzling is the claim in the table cited to support this point that in these victims death was observed to occur between 25.7 and 29.2°C. The mortality rate for this fatal range of hypothermia is not supplied, so the lethality of the lethal temperature remains undefined. The temperatures reached in the majority of the 80 to 90 victims who died are not reported. Moreover, because the demographic characteristics, nutritional state, and general health of this cohort are not described, it is impossible to determine whether the results apply to populations outside a concentration camp.

The Dachau Comprehensive Report states that in seven experiments the victims died 53 to 106 minutes after the start of cooling. Alexander reports, however, that a review of Rascher's experimental records and statements by his close associates disclosed that it took between 80 minutes and six hours of immersion to kill the naked victims, whereas the clothed men died after six to seven hours of cooling.10

The information on the lethality of the experiments is also inconsistent. In the Dachau Comprehensive Report, Rascher writes in one place that the hypothermia study was not designed to produce fatalities, and in another presents data on seven lethal experiments, and he refers to 13 deaths. In fact, two assistants testified that at least 80 to 90 victims died during the experiments, and only two were known to have survived the war, both of whom became "mental cases."16 , 17 The sequence is reminiscent of Rascher's disclosures on mortality in another study, on high altitude, which contained a similar chain of discrepancies.9

Figure 1. Figure 1. Reproduction of Figure 10 from the Dachau Comprehensive Report. The horizontal axis shows minutes, and the vertical axis temperature (°C). The German title may be translated as "Effect of combined rewarming treatment: warm bath, massage and light box." The water temperature was 8°C. The arrows and numbers (1 to 6) were superimposed by the present author. Translations of the corresponding notations from the German are: 1, in water; 2, period out of bath (no German notation); 3, warm bath; 4, massage; 5, light box; and 6, response to speech (regaining of consciousness).

Firm conclusions about the efficacy of several techniques of rewarming are offered, despite a paucity of supporting data. Detailed results presented in the form of time-based temperature curves are reported for only three groups of experiments. The graphs reveal that body-temperature recovery was fastest with immersion in warm water, but that rewarming and presumably survival were achieved with the other methods, too. The description of one set of experiments and the accompanying temperature curve in the Dachau Comprehensive Report show the quality of the reporting (Fig. 1). The text states that a method of rewarming with a combination of a warm bath and a body massage was tested, but in the supporting figure treatment with a light box is added at the end of the study. The number of experiments and the demographic characteristics of the victims in this subgroup are not specified. Nor are the temperature of the bath and the intensity of the electric heat source, or the frequency and timing of the measurements of temperature. Although no warming was instituted for approximately 12 minutes after the victims were removed from the ice-water bath, the temperature curve shows no "after drop" such as that previously described as being regularly observed. The duration of resuscitation in a warm bath is 10 minutes, according to the text, but it lasts 20 minutes in the figure.

The conclusion is drawn that immersion in a warm bath for rewarming is the best method of treatment, and preferential use of this technique is recommended. However, since survival rates — the ultimate criterion of the effectiveness of a rewarming technique —are not given in the Dachau Comprehensive Report, no judgment about the merits of the various resuscitative techniques is warranted, and the recommendation that a warm bath is the best therapy cannot be justified on the basis of the data. The credibility of the results has been compromised further by the postwar disclosure that most victims who were thrown into a tub of boiling water for rewarming died, making it probable that in fact rewarming in a warm bath had the highest mortality.18 Incidentally, the role of immersion resuscitation remains controversial to this day.22

The Dachau Comprehensive Report maintains, without any supporting data, that warm-bath rewarming had no undesirable side effects. With the grossly inadequate techniques of hemodynamic and electrocardiographic monitoring used at Dachau, circulatory failure and cardiac arrhythmias, the two most likely untoward reactions, could not be evaluated accurately. Therefore, the statement about the lack of harm is not justified.

According to the Dachau Comprehensive Report, death from cooling was caused by heart failure due to peripheral vasoconstriction and cold-induced structural myocardial injury. However, there is no mention of clinical signs of cardiac failure or evidence of myocardial damage at autopsy. Extensive experimental and clinical experience has clearly shown that contrary to the claim from Dachau, death from hypothermia is usually due to ventricular fibrillation, and cold does not injure the heart but instead protects it. Indeed, selective myocardial cooling is routinely used to preserve the myocardium during cardiac surgery. Appropriate electrocardiographic monitoring and histologic examination of myocardial tissue in the Dachau victims could have identified the true mechanism of death.

To support the concept that death invariably resulted from cardiac and not respiratory failure, the report advances the claim that breathing continued for as long as 20 minutes after "clinical standstill of the ventricle." This sequence of events is at variance with the time-honored observation that spontaneous respiration does not continue for long after the cessation of cardiac function, and it suggests that the investigators lacked the means or competence to recognize cardiac arrest. Another possibility is that the phenomenon of persistent breathing after cardiac arrest was fabricated.

The concept that local application of cold to the occiput and dorsal neck accelerates cooling was advanced by Himmler and is demonstrated convincingly in the Dachau Comprehensive Report with temperature curves from one set of experiments. Rascher also maintained that death and cerebral bleeding occurred only when the occiput and neck were submerged in the ice water, implying that immersion hypothermia does not result in death if the structures above the neck are kept out of the water. Although the scalp is an efficient heat-exchanging surface,23 I could find no evidence in the rich literature on induced or accidental immersion hypothermia that this relatively small area has such a pivotal role in the cooling response. The observation was probably fabricated; Gagge and Herrington remarked that the Dachau results may have been "exaggerated" to support Himmler's theory.24

The statement in the Dachau Comprehensive Report that cooling was complicated by cerebral edema and hemorrhage is at variance with the vast experimental and clinical experience on record. In animals, hypothermia shrinks rather than swells the brain.25 Cerebral edema has not been observed in cases of accidental hypothermia or surface or core-induced hypothermia for cardiac surgery.26 The last of these techniques is used in more than 250,000 operations annually in the United States alone without concern about the development of cerebral edema from hypothermia. Similarly, cerebral hemorrhage has not been observed as a result of experimental or clinical hypothermia. Thus, this report from Dachau probably represents a fabrication of data. It is also possible that brain injuries were inflicted by beatings or were sustained during the desperate struggles of the victims in the ice tank.