The Compendium of Kāśyapa 8.2.21

8.2.21

laghutvaṃ cāṣṭarātre ca nirāmajvaramādiśet
āpātalakṣyaḥ syādūṣmā tatkṣaṇādeti mārdavam

and lightness, and at the end of eight nights, one should declare it to be fever free from raw toxins. / The body heat may be perceived upon touch, and from that moment attains softness;