In English, "warm" and "hot" are usually interchangeable when ordering a hot drink. In my experience, "hot" is more frequently used.
I was corrected with 温かいコーヒー when asking for an 熱いコーヒー so I assume that my statement was incorrect.
Thus, I am curious as to why 温かい is the preferred adjective for ordering a "hot" beverage?
「熱い飲み物」 is used when we want to emphasize a drink's hotness.
「温かい飲み物」 is used for drinks that are properly hot.
My friend often says 「熱いお茶をください」 when she wants to emphasize its hotness.
One of the definitions for 温かい is "(pleasantly) hot".
Thus, requesting a beverage that is 熱い is akin to asking for an "(unpleasantly) hot" drink.
According to the dictionary:
熱い: When the temperature is excessively hot.
暖かい: neither hot nor cold, a comfortable temperature.
あつい(熱い)温度が著しく高く感じられる。
https://dictionary.goo.ne.jp/jn/4736/meaning/m1u/熱い/
あたたかい(暖かい／温かい)物が冷たくなく、また熱すぎもせず、程よい状態である。
https://dictionary.goo.ne.jp/jn/4532/meaning/m1u/暖かい/
