Jesse Harvell describes it on Pitchfork in this way:
Health and Efficiency is This Heat’s masterpiece. The title track is, in a complete turn of events for these doommongers, a hymn to the restorative powers of sunshine, and their most traditionally rocking song, at least until it veers off into an extended instrumental slalom with some of Hayward’s most intricate (and violent) drumming. “It seemed to be a quite radical idea to be healthy, happy, acknowledging the sun,” Hayward says in the liner notes. “We’ve all got the same bodies; it’s international.” The B-side, “Graphic/Varispeed”, is an extended experiment in tape loops and studio manipulation, as you might have guessed from the title.
You can now listen the EP as a full album on Youtube: