Great work, I really like the theme interpretation and the gameplay!
I agree with others that the jump controls are a bit difficult to use, so I often lost due to a wrong jump instead of temperature. It's also strange that during daytime you can keep cool by staying in the shade, but as soon as night starts, you heat up very fast due to the ambient temperature still being super hot (while actually, everything is in shade by definition and you should therefore have the same effect - or more cold - than when protecting yourself from the sun).