In Part 1, Section 5, what do the two machines do in Fahrenheit 451?
In this part of the book, Millie Montag comes close to killing herself when she takes her whole bottle of sleeping pills all at once. Guy Montag has to call a couple of men to come and save her life. The men bring two machines with them to try to save her.
Both of the machines are meant to clean all the poisons out of her body. One of them is inserted into her stomach and it pumps out the contents of that organ. This will get rid of what's left of the pills in there.
The second machine actually has to take out all her blood and replace it. The man says that if you don't replace a person's blood, they will die even after their stomach is pumped.
From these two machines, we can see that this sort of problem is very common in this society. That tells us the people must be fundamentally unhappy.