Hypercapnia and Gas Exchange Under the Avalanche Snow Model (HyperAvaSM)

Inclusion Criteria: * Participants were volunteers from the Czech Army forces, studying at the Military Department of the Faculty of Physical Education and Sport, Charles University in Prague. All subjects were healthy and fit, classified as ASA I, all without a smoking history. The volunteers were highly motivated to participate in the experiment. The entrance examination, completed before the start of the study, included these tests: electrocardiography, blood pressure, spirometry, and assessment of the health conditions and family anamnesis by a physician with a specialty in anesthesia and critical care. Exclusion Criteria: * The exclusion criteria were Tiffeneau Index less than 0.70 and any cardiovascular or respiratory condition.