EntityQ2739914· pop 25· linked from 36 articlesArmstrong limitSign in to savealtitude above which water boils at human body temperature, making it absolutely impossible for humans to survive unpressurized; approx. 18–19 km above sea levelConnectionsstandard atmosphereEntitypressurized cabinEntityVenusEntityMount EverestConcepttongueEntityDead SeaEntityurineEntityatmosphere of EarthEntitytearEntityhuman bodyEntitycirculatory systemEntityblood vesselEntitydigital object identifierEntitysalivaEntityneurologyEntityatmospheric pressureEntityUnited States Air ForceEntitypascalEntityOlympus MonsEntityboilingEntityCategoriesAltitudes in aviationAtmosphereAviation medicineHuman physiologyHuman spaceflight