Such changed chemicals (mainly physically) may lay under soil surface several months and wait for humidity and temperature changes, and for instance after snowfall start emanate absorbed heat energy (similar for instance as copper sulphate anhydrous after adding water emits great exotermic energy power).
Vile kemikali iliyopita (Hasa Kimwili) inaweza kuweka chini ya udongo miezi kadhaa uso na kusubiri kwa mabadiliko unyevu na joto, na kwa mfano baada ya Snowfall kuanza itakayotolewa kufyonzwa joto nishati (Sawa kama kwa mfano shaba sulphate isiyo na maji baada ya kuongeza maji hutoa exotermic kubwa nishati ya umeme).