There are monorails between the hotels. Mandalay Bay -> Luxor -> Excalibur
Then you have MGM -> Bally's and Monte Carlo -> Bellagio -> Treasure Island. I believe they are building a single monorail that connects all the strip. I'm not sure if they are finished with it. But the point is that you are going to spend most of your time indoors. Enjoy the "free" A/C.