Kings of Leon meltdown due to more than the Texas heat?

(CBS) The Kings of Leon, which cut short a Friday night show in Dallas and postponed a Saturday concert in Houston, ostensibly because of the heat, has added a make-up Sept. 21 Dallas show to its tour calendar.

That show is open to all who held tickets for the shortened July 29 show. According to a statement by the band, ticketholders unable to attend on Sept. 21 will get a refund.

According to a report in the New York Times, lead singer Caleb Followill left the Dallas stage, promising to return but he never did.

"I'm about to fall down here because I'm so goddamn hot," he told the audience.

Over the weekend, however, tweets by his brother, bass player Jared Followill, hinted at trouble among band members.

"Dallas, I cannot begin to tell you how sorry I am. There are internal sicknesses & problems that have needed to be addressed. No words," he wrote, adding in another message, "I love our fans so much. I know you guys aren't stupid. I can't lie. There are problems in our band bigger than not drinking enough Gatorade."