68°F (20°) is my "neither hot nor cold" point; ideal cabin temperature range is 66°F (~19°C) - 72°F (~22°C). Warmer than that, I have a hard time falling asleep (even if I want to). 76°F (~24°C) and above makes me extremely uncomfortable. If it's cold, all I need is a blanket to make me happy. If it's hot, I'll complain to the FAs.

EPS recommends: Bright Backlight Travel Alarm Clock With Temperature from Brookstone, item number B218917.