the_excerpt() in head tags

Edit:
OK, it was simple. No idea why I did not come up with this last night.

Simply added a loop in the head tags. Here is the code I am using.

<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?><?php $out_excerpt = excerpt(5); echo apply_filters(’the_excerpt_rss’, $out_excerpt); ?><?php endwhile; endif; ?>

Original post:
Hi,

I am hoping this one is an easy one to solve but I have been unable to find anything to help me.

I am looking to be able to use the_excerpt() in the head tags. When placed there at the moment, it simply outputs nothing.

Any help appreciated. Thanks.