You can try an aluminum drip tip in place of the rubber tip on the carto. Takes a lot of heat away from the vapor. As NGIB said though, that carto will still get pretty warm being on that long.
You may quickly find, taking hits that long, the blu
batteries don't last long. You may be a perfect candidate for a larger battery device.
If you refill your cartos, a stronger nic
juice may help right at first to give you a better hit.