It made Nadia unreasonably nervous to leave the two 16Ds behind and walk into a city; and she was not reassured once through the lock, when she saw that most people inside were wearing their walkers and carrying their helmets with them, ready for depressurization if it came.
I've been waiting for a Heinlein reference (besides Waldoes) and it looks like this is as close as we're going to get. Something right out of "The Moon is a Harsh Mistress".
