The Compendium of Caraka 6.3.44

6.3.44

accumulated and irritated pitta, through the sun's fire in autumn, / swiftly produces fever, and kapha is its secondary force.
By the very nature of the discharging season, there is no danger from fasting in that case. / Kapha accumulated by sweet waters and medicinal plants
in winter is heated by the sun and provoked in spring; / therefore fever arises through kapha in spring.