WordPress get_categories & listing recent post thumbnail

Did some playing about, managed to get it working.

 <?php
/*
Template Name: Festivals - United States
*/
?>
<?php get_header(); ?>

        <div id="left_full">

        <?php
$args = array(
  'orderby' => 'name',
  'order' => 'ASC',
  'child_of' => '3592'
  );
$temp_query = $wp_query;
$categories = get_categories($args);
  foreach($categories as $category) {
query_posts("posts_per_page=1&cat=$category->cat_ID");
if (have_posts()) : while (have_posts()) : the_post();
            echo '<div class="interview_item">';
    echo '<div class="interview_thumb"><a href="#" rel="bookmark">'; the_post_thumbnail('interview-thumb'); echo '</a></div>';

    echo '<h1><a href="' . get_category_link( $category->term_id ) . '" title="' . sprintf( __( "View all posts in %s" ), $category->name ) . '" ' . '>' . $category->name.'</a> </h1> ';
    echo '</div>';
endwhile; endif;
    }
$wp_query = $temp_query;
?>

        </div>

    </div>

<?php get_footer(); ?>