@RobertK took the words out of my response-post before I got around to it. However, I would like to add that in Paṭiccasamuppāda 5th Method Meditation Manual, the yogi is instructed to discern the materiality of his deceased body. He will find mostly heat born materiality…
Why only mostly 
Quote from PAṬICCA SAMUPPĀDA STAGE (5TH METHOD) (Pa-Auk Meditaiton Manual)
(English translation has not been edited yet.)If the meditator does not find the NāmaRūpa of Maraṇāsanna when investigating and reflecting by insight towards the past and if sees only the appearance of being dead then discern the 4 Great Elements of that corpse. Then he will find only small particles. Analyse these small particles. Mostly, one will find the groups of Rūpa where Ojā is the 8th and which are produced by Tejo dhātu called Utujaojatthamaka Rūpa.
It is mentioned as ‘mostly’ because sometimes a meditator may find the Rūpa Kalāpa of some living maggots existing in that corpse. Therefore, sometimes a meditator may find Transparent Kalāpa and Non-transparent Kalāpa mixed together in the corpse. However, that of the corpse, there are only Utuja Rūpa which are Non-transparent Utuja Rūpa.
After having discerned the Rūpa of that corpse, further discern towards the past gradually to discern the NāmaRūpa that arose at the time of near death. If able to discern the NāmaRūpa of near death, then discern the object of the Maraṇāsanna Javana which was arising at the time of near death.
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