Where does “hypopyrexia” come from?

hypopyrexia (English) comes from English pyrexia, from Latin pyrexia, from Ancient Greek πυρεξία, from Ancient Greek πυρετός, from Ancient Greek πῦρ, from Proto-Indo-European péh₂wr̥ — bonfire; spelt.

hypopyrexia (English): An unusually low body temperature

Definitions

An unusually low body temperature

Ancestry of “hypopyrexia”, step by step

hypopyrexia traces back through two separate lines of ancestry.

via English pyrexia

Step	Language	Word	Meaning
1	English	pyrexia	Fever; Trench fever
2	Latin	pyrexia	—
3	Ancient Greek	πυρεξία	feverishness
4	Ancient Greek	πυρετός	heat; fever
5	Ancient Greek	πῦρ	a fire; lightning; a fever
6	Proto-Indo-European	péh₂wr̥	bonfire; spelt

via English hypo

Step	Language	Word	Meaning
1	English	hypo	Melancholy; a fit of ‘hypochondria’; a morbid...
2	English	hypo-	Below; beneath; under; Deficient; less than...
3	Ancient Greek	ὑπό
4	Proto-Indo-European	upó	under, below
5	Proto-Indo-European	h₃ewp-	—

Every word from Proto-Indo-European péh₂wr̥ →Every word from Ancient Greek πῦρ →Every word from Ancient Greek πυρετός →