Hot sleep

"Hot sleep" technology uses electronic nerve stimulation to induce a perpetual state of unconsciousness, with just enough muscle stimulation to avoid extreme degrees of atrophy. A subject under hot sleep can be kept unconscious for years, or even decades, without becoming too horribly damaged by the process.

Though universally condemned by social activists, hot sleep technology has been permitted by United Earth in cases where no other restraint can be relied upon -- that is, to keep imprisoned the most powerful and dangerous metahuman criminals, in Stronghold and Tranquility and elsewhere. Of course, there are also rumors -- sometimes substantiated -- of its use by less scrupulous groups.

Note that hot sleep is not suspended animation; the subject ages normally. See Cold sleep.