A figure of speech to signify how someone feels when they're nervous, anxious, worried, afraid, ashamed, or even shy.
This is typically an
unpleasant feeling, because
you will see something that hurts you, worries you, or scares you.
I am
feeling the heat go up my body whenever I see a picture of that girl, because
I miss her terribly, but I know at the same time that she doesn't want me, so I will never get the chance
to be with her.