The Compendium of Bheḷa 6.11.2

6.11.2

mriyate hy upaśānte ' gnau yukte coṣmaṇijīvati | tasmāt prāṇāyuṣī vidyādagnimūle śarīriṇām ||

For when the fire is extinguished, one dies, and when warmth is present, one lives; / therefore one should know that the vital breaths and life of embodied beings are rooted in fire.