Approaches for Effcient Payload Encoding

Hi, I send from my Arduino a temperature (float on Arduino) as 4 bytes:

temp: 20.12
bytes send : 0xD0, 0xF6, 0xA0, 0x41

Any idea how to convert this ‘back’ to 20.12 using payload functions?

I tried the example from above but that doesn’t handle negative values well.