Evan Tanner -- Cause of Death

9/9/2008 3:00 PM PDT

Evan Tanner -- Cause of Death

We're now told the coroner now has a theory on why former UFC champ Evan Tanner died -- heat exposure.

As we first reported, he went missing late last week after taking a lone expedition in the desert. We reported Tanner text messaged a friend that he needed water. A search team found his body yesterday.

There's something weird about this case. Tanner blogged that going into the desert could be life-threatening and he needed the proper equipment. Water should be the first thing that comes to mind, yet he was almost immediately in need of H2O.

Nevertheless, 110+ degree heat is always dangerous. Sad story.