Well, it would be possible to walk between Epcot and Hollywood Studios. If you exit the International Gateway at Epcot, you can then walk toward the Boardwalk Resort. Go past WDW Dolphin and Swan and on to Hollywood Studios.
To save on your feet, however, I would recommend hopping aboard a Friendship boat at this same exit. You will exit between United Kingdom and France in Epcot's World Showcase. Once you exit the turnstiles, proceed to your left toward the water and you'll see the Friendship boat dock.
It is a long but beautiful walk. It was also be very unpleasant in hot and humid weather.
Walt Disney World is twice the size of Manhattan. In hot weather, you'll be glad for any mode of transportation to your destination. Utilize the buses, boats, monorails and taxis, if you do not have your own vehicle.
Have a magical vacation!