I’d agree with the other response that tepid is the best word for this, but if you don’t like that one you could use chilly, chill, brisk, or even just the word cool. The word cool implies on its own something that’s just slightly cold.
Body temperature > room temperature. Lukewarm/tepid kinda occupies the space between. It is technically warmer than its surroundings, but does not provide a substantial warming effect to the body.
Lukewarm is used almost exclusively for water, whereas room temperature is a reference to air temperature (either the current or a desirable one) Water and air exchange heat with the human body in different ways and at different rates. Room temperature air is fairly neutral to the body, but a 68F/20C swimming pool is rather chilly, and a 90F/32C room is not what I would call lukewarm.
Warm & cool both have an implication of comfort whereas hot & cold have more an implication of danger or discomfort. Maybe there is something to thinking about these on more than one axis: relative temperature vs desirability or pleasantness.
Context is weird. For things that are supposed to be “hot”, either “cool” or “cold could mean room temperature, above room temperature but also not quite “warm”, or hotter than “warm” but below a target, expected, or usable temperature.
“luke” derived from “lew” or “lewk” or “leuk”, in Middle English, which meant “tepid” (slightly warm). This in turn came from the Old English adverb “hlēowe”, which means “warm or sunny”. Finally, “hlēowe” came from the Proto-Germanic *hlēwaz, meaning “warm”.
The word “lukewarm” popped up around the 14th century as meaning “slightly warm”. Within two centuries, it also began having a figurative meaning, that of “lacking in enthusiasm”.
I always thought it came from that bible verse where Jesus says that if your faith is lukewarm he will spit you out of his mouth. I figured he was insulting Luke
True!
But that’s kind of also true for all temperature words. What’s hot for one thing is cold for another, etc. we’ve still made these other words anyways. That could be an entirely other shower thought
if that’s the case what’s the difference between warm and hot i always thought lukewarm was the warm side and tepid was the cold side of medium. i don’t think there true medium where you can’t tell if it’s warm or cool side.