Given that Marsha E. Ackermann teaches in Michigan, it’s no wonder that she expresses ambivalence about central air in her book Cool Comfort: America’s Romance With Air-Conditioning. That’s always been the problem with naysayers such as Henry Miller, who shared his Luddite tendencies with us in The Air-Conditioned Nightmare: If they lived where we live, they too would pray to their air conditioners as gods. Nevertheless, Ackermann’s book raises intriguing issues; especially interesting is her analysis of air-conditioning ad campaigns of the ’40s and ’50s, which employed blatant racist and sexist stereotypes to hammer home the point that advancements in civilization were contingent on, in sociologist S. Colum GilFillan’s memorable words, “the coldward course of progress.” Still, anybody who’s spent an August day in D.C. would be hard-pressed to disagree with engineer Edward P. Bates, who in 1895 declared, “Ventilation comes next to godliness.” Ackermann speaks at 7 p.m. at Olsson’s Books and Records, 418 7th St. NW. Free. (202) 638-7610. (Mike Little)