The active ingredient in Eight Hour cream is Petrolatum ( Petroleum) . This product is over priced Vaseline, which is known not to really be the greatest thing for your skin.
It works by sealing the skin from the enviroment. While this can be useful occasionally, if this is done regularly ( say if you were using Eight hour cream as you daily lip balm) then it is going to be detrimental. The skin is unable to breath and absorb moister from the air, and gets out of the habbit of doing so. You then become dependent on using the product all the time. You are better off using a balm that helps the skin to heal and function normally.
I always have a tube handy, especially with cracks, really dry skin. Fantastic for cuts etc as well. I have even used it on my lips when they have been very dry.