[Plugin: Heatmap Plugin] Use wp_print_scripts instead of wp_head

Swap this:
add_action(‘wp_head’, ‘heatmap_set_wpurl’, 1);

With this:
add_action(‘wp_print_scripts’, ‘heatmap_set_wpurl’, 1);

Scripts should load after styles. Scripts block when they load, that stops everything on your page until the script is loaded. Styles don’t block. Plus you want your style loading first anyway.

https://www.ads-software.com/extend/plugins/heatmap/