Just saw Mayweather interviewed on ESPNews. And its the second interview were he mentions that Hatton needs to get used to the altitude. What altitude is Mayweather talking about?
"The climate and altitude in Las Vegas can be difficult to deal with. But dont let that stop you from visiting! Come prepared. When outdoors, be sure to use lip balm, sun block, or wear a hat and long sleeves. I forgot about my lips and quickly got sunburned. My new pouty lips may be stylish, but they hurt! Carry a water bottle if you do plan to walk. The week we were there the high temperatures were 100-104ºF. The altitude proved difficult for me in the long walks between neighboring establishments." http://community.iexplore.com/planning/journalEntryOverview.asp?JournalID=55467&n=Nothing+Vague+about+Vegas
the fighters will be inside wehre its humid and the air thins then add the altitude...it makes sense but Hatton has had time to catch up to it he has been in Vegas sparring and working out he should be fine.
I believe that hatton already had two fights to get prepared to the altitude factor in Las Vegas. Maybe he was using a second meaning like the level of this fight being set too high for Hatton's mental reach?...