Charak Samhita
शीते शीतानिलस्पर्शसंरुद्धो बलिनां बली। पक्ता भवति हेमन्ते मात्राद्रव्यगुरुक्षमः ॥९॥
॥ Diet and lifestyle guidelines in Hemanta ritu (Winter season)॥ Status of agni: During sheeta kala (hemanta) due to the contact of cold wind, the agni (digestive power) of strong/healthy individuals gets trapped in the body (like in a closed chamber) and becomes strong or powerful enough to digest food that is inherently heavy and excess in quantity.
english translation
zIte zItAnilasparzasaMruddho balinAM balI। paktA bhavati hemante mAtrAdravyagurukSamaH ॥9॥
hk transliteration by Sanscript