To Chill
Transitive verb and Godan verb
ひやす
指をドアで挟んじゃって、今氷で冷やしてるの。
My finger got caught in the door and I’m chilling it with ice now.
冷たい is "cold." This is the verb version, so you're making something cold. This word is to chill something.
To chill something, you need to apply cold, not heat (ひ).