★★★★★
It's usually a sign I'm slightly dehydrated. I found this out when I worked at a store where they had a blower-heater at the entrance - making the air very dry - combined with being busy and not having the time to drink during busy hours.
For dry, painful cracked lips, a 30 minute glycerine lip treatment will help. Simply put a thick layer of glycerine onto your lips, as thick as possible, and let it sit for at least 30 minutes. Leave it alone, don't smear it out or touch it. It's sticky and sweet, so make sure you have a straw at hand if you get thirsty...
After 30 minutes or longer, gently remove the glycerine with a soft tissue. In most cases, the lips will be perfectly soft again, and even the painful cracks will have healed.
I personally don't feel glycerine is something for every day use, but it works wonders when needed.
