Fowarded Bolt's question -- How can the neoprene insulate beer and still benefit from the ice pack that the website is selling? -- to Brooks Lambert, inventor of the Beerbelly.

Here is Lambert's response: "It’s important to remember that the beer is held in a separate polyurethane pouch or bladder that is then inserted into the neoprene sling which has a pocket to hold the bladder. This way the bladder is held in place and insulated on all sides.

Then if the user wants, they can add the Pleasure Extender “hot/cold” pack into the neoprene pouch next to the bladder offering additional cold time.

Without the cold pack the contents stay cold for a couple of hours depending upon how cold it was when it started and how warm it is where it’s being used. The cold pack adds about another hour again depending upon the previously mentioned variables."

So you can, Lambert says, have your beer cold and your stomach warm.