We could write a book on the many reasons we love the Tattered Cover's LoDo store, among them the old, creaky floors; the chipper, non-creaky staffers; the huge selection of newspapers and magazines; the overstuffed chairs that are just the place to read those newspapers and magazines (or take a nap); the auditorium that frequently offers lectures and book signings; the fact that both Tattered Cover stores still let you write checks without showing ID. But at this time of year, what we appreciate most about the Tattered Cover LoDo is how it keeps its cool. Although the bookstore is housed in the century-old Morey-Mercantile Building, it boasts a thoroughly modern air-conditioning system, one that keeps the indoor climate completely under control. That's important to books, and it's important to booklovers. Chill out.