I read that the further away from body temperature, the harder it is to taste. Which I suppose makes a fair bit of sense. So you can taste the most flavours and notes at around 36-37°C. I’d definitely agree with that, I usually drink espresso which obviously cools a fair bit quicker and my last sip or two are usually around body temp and it’s the best tasting. I do like the warmth of it at a higher temperature though. Feels nicer on the throat.