The Compendium of Caraka 6.3.281

6.3.281

jīrṇajvaraharaṃ kuryāt sarvaśaścāpyupakramam/
śleṣmalānāmavātānāṃ jvaro+&anuṣṇaḥ kaphādhikaḥ//
&` 'anuṣṇo' iti pā-.
paripākaṃ na saptāhenāpi yāti mṛdūṣmaṇām/
taṃ krameṇa yathoktena laṅghanālpāśanādinā//

and he should carry out measures entirely capable of curing chronic fever.
In persons of phlegmatic constitution without vāta, whose fever is not hot and has an excess of kapha,
[the fever] does not reach digestion even after seven days because of their dull heat.
Having treated him for ten days in the prescribed sequence by fasting, light eating, and the like,