Morph
* jumbo * giant * hefty * large
Delay.
empty
Another five-letter word for 'change' is 'alter.'
Stall.
change 'e' and you get noon
The five letter word that refers to heat is steam. When a liquid evaporates, it evaporates releasing steam whose temperature is high.
swap
site sireside
Anagram
silt, slit
You can change the 'm' to a 't' to make wart.