Heatmiser was an American rock band, formed in Portland, Oregon, in October 1991. Consisting of Elliott Smith (guitar and vocals), Neil Gust (guitar and vocals), Brandt Peterson (bass; later replaced by Sam Coomes, frontman of Quasi) and Tony Lash (drums), they were known for their well-crafted lyrics and songs often featuring the juxtaposition of melancholic and cheery words and melodies. Elliott Smith's pop-oriented songs provided a contrast to Neil Gust's darker compositions, yet both songwriters explored themes such as anger, alienation, loneliness and despair.

In 1987, while both of them were attending classes at Hampshire College in Amherst, Massachusetts, Neil Gust and Elliott Smith met and formed a band, Swimming Jesus. In addition to covers of songs by Ringo Starr and Elvis Costello, the pair performed original songs in clubs in nearby Northampton. The two were prolific: besides Swimming Jesus, Gust and Smith had another pre-Heatmiser college band, featuring "a friend named Dylan and two others", and recorded "stupid and embarrassing" music on rented four-track recorders with "poetry on top", recited by a "Southern Californian stoner-photographer guy" friend.

Following their graduation from Hampshire College in 1991, Gust and Smith returned to Portland, Oregon. In Portland, Gust and Smith formed Heatmiser with Smith's high school friend Tony Lash, who'd been working at a recording studio and playing drums in local band Nero's Rome. Early versions of Heatmiser included Jason Hornick. In high school, Lash and Smith played together in the school band—Lash played flute, Smith played clarinet—and Lash played drums in Smith's band Stranger Than Fiction. Lash and Smith had bonded over a mutual love of Rush, and outside of their high school band class, they began to work out "insanely complicated songs" together, recording after school with Eric Hedford, future Dandy Warhols drummer. Tony Lash recalled about recording with Hedford: "We recorded all the backing band tracks for [Stranger Than Fiction's] Still Waters More or Less at Eric Hedford's house in 1985–86. He had a basement with drums, mics, a piano, and a mixer. He helped us set up, but he didn't play on any of it."

With Heatmiser in need of a bassist, a high school friend suggested Brandt Peterson to fill the position. Peterson had played in a few punk bands, but "was feeling ambivalent about another." Smith convinced him to join Heatmiser, at least until their February 14, 1992 live debut at Portland's X-Ray Cafe. Over the next few years, Heatmiser was a regular act at local Portland venues like the X-Ray Cafe, screenprinting shop Hand Prints, and La Luna, whose cheap, packed Monday night concerts were a hub for the city's twenty-something underground social scene.

Brandt Peterson played bass on the albums Dead Air and Cop and Speeder, the Yellow No. 5 EP, and several singles. He wrote at least two songs for Heatmiser: "Just a Little Prick", released on The Music of Heatmiser, and "Glamourine", a "bass-line with lyrics" that remains unreleased. Peterson did a cover design for the Yellow No. 5 EP that ultimately wasn't used; additionally, he did the cover art for Dead Air.

Peterson left the band in August 1994 and was replaced by Sam Coomes, a friend of Smith's. Coomes played on Heatmiser's last album, Mic City Sons, and on tour. Coomes has a modest view of his contributions to the album: "There's two levels of playing for me [on Mic City Sons]," he added, laughing. "Decent and could be better." After Peterson's departure, the band "struggled [on tour] to draw the same crowds they'd built in Portland. They played wherever they could, even a laundromat."

Smith discussed Coomes' entry into the band:

Sam [Coomes] came in sort of towards the end, initially out of the kindness of his heart, because Heatmiser had a different bass player who was so confrontational that we eventually kicked him out. Boy, that was an unpleasant thing to do. I mean, kicking someone out of a band is like breaking up with somebody. At least in the band it was, because everybody except for me was really into it. I, to a certain degree, was pretty invested in the band emotionally or whatever. It actually came down to me kicking [Peterson] out, even though everybody agreed to it. We met up to do it, but then [he] started asking everyone personally if they wanted him out. Then it came to me and I said I wanted him out. That guy was just such an asshole. That guy I don’t really care that much about. I mean, he was an okay guy, and we were friends for a while, but he just kind of worked up everybody’s nerves. His sense of humour was such that he always had to be making fun of somebody. He was just not a good time.