Anyone know of a handguard option for the AR carbine that stays cooler and doesn't weigh anymore than the standard handguard.  This is for a KISS carbine, lwt/flattop with collapsable.  The thing is, those handguards get HOT after a mag or two.  Not looking for FF or anything fancy, just something that vents better or stays cooler (which I assume means vents better rather than trapping heat in there).   Don't like vertical grips either.  I haven't found that the M4 grips stay all that much cooler with the lwt barrel.