Standard Atmospheric pressure is 1 bar at sea level. 0.75 bar is less then 1 bar. In the standard model Atmospheric pressure is 0.75 Bar at 8000 feet. That is why radiators boil over more often at high altitudes then low altitudes. It takes less heat to boil water at high altitudes then low altitudes.
If you are exposed to the vacuum of space. You will not die from asphyxiation. You will die from being boiled alive as the water in your body boils due to the extremely low pressures. That that low of pressure the heat of your body is enough to boil water.






