I assume that you know how to show field label on front (there is few options), one option is:
echo $page->fields->summary->label; // for field with name "summary"
But today I had a problem how to show field label depending on the current page template (example: in template "member", "summary" field label is override to "Personal info"). In that case, previous example will not give you desired result.
To get field label in that case, this is what works:
$page->getField('summary')->label; // result would be "Personal info"
Maybe this is helpful for someone.
Regards.