The suffering to which the wicked are subjected takes place in the postmortal spirit world. This is hell, both a place and a state of mind. Concerning hell as a state of mind, Joseph Smith explained:
“A man is his own tormenter and his own condemner. Hence the saying, They shall go into the lake that burns with fire and brimstone. The torment of disappointment in the mind of man is as exquisite as a lake burning with fire and brimstones.”
(Teachings, p. 357.)