The Compendium of Caraka 6.3.8

6.3.8

jvarāvasṛṣṭo rakṣyaśca yāvatkālaṃ yato yataḥ/
praśāntaḥ kāraṇairyaiśca punarāvartate jvaraḥ//

for how long and from what things one freed from fever should be protected, / and by what causes a fever that has subsided recurs;