My mad (as in crazy, certainly not angry) scientist has a project to help the Earth by shrinking all of the humans. He figured out a way - not important - to shrink himself and a vessel about car-sized. He is now about 1 cm tall, and everything in his vehicle shrank (atoms, cells, bacteria, himself, etc).
There are a whole slew of issues about bugs attacking, etc., but I am interested only in the biological limitations when he opens the door of his vessel, and breathes in fresh air, or tries to drink a drop of water, etc. You may even imagine it's a mostly sterile environment.
What are the biological limitations to living in our environment if we shrank to 1cm in height, proportionally.
Note 1: This isn't as small as the movies Honey I Shrunk the Kids, or Innerspace; simply 1cm in height.
Note 2: The simple past tense form of “shrink” is “shrank” and the past participle is “shrunk”; it should be “Honey, I Shrank the Kids,” not ”Honey, I Shrunk the Kids.” “Honey, I've shrunk the kids” would be standard, and also grammatically acceptable is “Honey, I've shrunken the kids”.