cool, v.⁴ — Green’s Dictionary of Slang

cool v.⁴

[the calming effects of the drug, either as ending withdrawal symptoms or simply removing oneself from ‘reality’]

(drugs) to sell heroin; to inject (someone) with heroin.

1973

A. Childress A Hero Ain’t Nothin’ 71: ‘You lookin for somebody round here?’ [...] ‘Cool me, that’s what.’ [HDAS].