 Most of these practices, but not all of them, involve the infliction of extreme physical pain. For example, sleep deprivation does not necessarily involve the infliction of extreme physical pain. However, all of these practices involve the infliction of extreme physical suffering, e.g., exhaustion in the case of sleep deprivation. Indeed, all of them involve the intentional infliction of extreme physical suffering on some non-consenting and defenceless person. If A accidentally sears B with hot irons A has not tortured B; intention is a necessary condition for torture. Further, if A intentionally sears B with hot irons and B consented to this action, then B has not been tortured. Indeed, even if B did not consent, but B could have physically prevented A from searing him then B has not been tortured. That is, in order for it to be an instance of torture, B has to be  defenceless.[4]