The Valley of the Sun has always been harsh to those who can't handle the heat. When Scott Smith wakes up as a female unicorn, she learns that everything's worse when you're a quadruped alone in a desolate city. As the days heat up and the hunt is on for food, water, and power, even the simplest tasks become impossible. This is how she fares as a unicorn mare.
This is a side story to Starscribe's The Last Pony on Earth.
(Rated Teen for some light swearing and talking about sex)