Last October, when Spencer Fronk and Andrew Palmquist opened Number Thirty Eight — a 31,000-square-foot-plus spot in RiNo — they promised they'd host outdoor shows even in the colder months on the venue's massive stage, with its state-of-the-art lighting and sound systems. Sure enough, Number Thirty Eight, so-named because Colorado was the 38th state to join the Union, has lived up to that promise, featuring local acts a few nights a week, along with some national crews. While most of the shows haven't had a cover, reservations are recommended — and needed: This new spot quickly became the hottest in town.