mesophile

noun

me·​so·​phile ˈmez-ə-ˌfīl  ˈmēz- 

ˈmēs-,

ˈmes-

variants also mesophil

-ˌfil 

: an organism growing at a moderate temperature (as bacteria that grow best at about the temperature of the human body) compare psychrophile, thermophile