It's unfair to expect these animals to pull the carriages around in the intense Charleston heat. They should find some other way of doing these carriages tours, so it does not involve horses. The summers in Charleston can be around 100 degrees, and no animal should have to pull a carriage full of people, and get in the way of traffic.
http://www.change.org/petitions/classic-carriage-works-llc-end-all-horse-drawn-carriage-rides-in-downtown-charleston