As with all instruments, you'll want to avoid extreme temperatures, cold or hot.  Otherwise, there isn't much to it.  We highly suggest you use a ukulele humidifier like this one with all of our solid top models.  A solid top instrument can dry out much easier than a laminate one, and the symptoms of dryness, including sharp fret ends, cracking, and a sinking top, are not covered under warranty, so take care of that thing!