My love is lyke to yse, and I to fyre;
how comes it then that this her cold so great
is not dissolv'd through my so hot desyre,
but harder growes the more I her intreat?
Ice  and  fire  are polar opposites. He uses this simile to contrast his “burning” passion with her “cold” unresponsiveness. 
 
 Opposites attract…right?
Amoretti: Sonnet 30