Simple in its design, the study provides relatively clear evidence of the utility of chest ultrasonography in detecting and following the course of pulmonary edema formation at high altitude. While the authors deserve credit for conducting this study in a remote environment with very limited clinical resources, it should be noted that the study is not without limitations. For example, although a blinded observer assessed the ultrasonography data, the person performing the ultrasound was not blinded as to the clinical status of the patient. Given that obtaining good ultrasound images is highly operator-dependent, the lack of adequate blinding is not an insignificant concern. In addition, although cardiogenic causes of pulmonary edema are unlikely in the clinical setting in which the authors were working, they did not take any steps to rule out a cardiogenic source of the comet tails by, for example, assessing left ventricular function or pulmonary capillary wedge pressure. Finally, as the authors note, this study represents the first use of this technique in the evaluation of HAPE, and, as such, the results have yet to be validated in further studies. Although worthy of consideration, none of these issues appear to seriously undermine the results of the article.