Without a coat is preposition in " Don't go (without a coat)".
Nirvana is a place of perfect peace and happiness, like heaven. In Hinduism and Buddhism, nirvana is the highest state that someone can attain, a state of enlightenment, meaning a person's individual desires and suffering go away. This belief emphasizes meditation and how much it helps achieve this state.
In the sentence, the figurative language is "like smokstacks".
