The Armstrong Limit is the altitude on Earth above which water boils at the temperature of the human body due to low atmospheric pressure (
https://en.wikipedia.org/wiki/Armstrong_limit). This would be very relevant on the moon because a human would instantly die without a properly pressurized suit or environment, as the moon has no atmosphere. Did pressurized suits capable of allowing humans to survive on the moon exist when the Apollo missions took place, and do they exist today?
EDIT: I found out that the surface atmospheric pressure on the moon is about 0.3 nano-pascals (
https://en.wikipedia.org/wiki/Moon#Atmosphere). Did the space suits supposedly used on the Apollo moon missions allow humans to survive this low pressure, and would any suits today allow humans to survive in it?