A sub-type of Nāma (body-making) Karma,
the Udaya (rise) of which is responsible for spontaneous emission of hot light radiation from the body of a Jīva (living being), which itself, by nature, is cool.
yadndayāt jantuśarīrāṇi svarūpeṇānuṣṇānyapi uṣṇaprakāśalakṣaṇamātapaṃ kurvanti tadātapanāma.(Prajñā 23.38 Vṛ Pa 473)
- Udyotanāma.