Heat Seek started in February 2014 when William Jeffries was up late one night in the cold at the Flatiron School, tinkering with a temperature sensor. He got a basic graph of the temperature sensor working, and wrote a blog post about how the technology could be used to help people who don't get access to adequate heat in the winter. He'd personally dealt with the problem when he moved to the East Village in 2011, and cited an I-Team New York article about the issue in his blog post. His classmate Tristan Siegel saw it and said his mother was a social worker with patients who could use the technology. With some equipment purchased by the school, they monitored Heat Seek's first apartment in the South Bronx. Within a few weeks, they had captured temperatures well below the legal requirement. At it's coldest, it got down to 53ºF in the apartment.

William's mother had worked as a public defender in the city and soon Stephanie Rudolph, an attorney for the Urban Justice Center, caught wind of the project. She brought another two apartments into the project and the Urban Justice Center became Heat Seek's first community partner. At that point another classmate Daniel Kronovet (now Heat Seek's board chair) started volunteering with the project, and the group entered the NYC BigApps competition. From there, the project picked up a lot of volunteers, including William's old roommates Jarryd Hammel and Tom Hunter from that cold apartment in the East Village. Jarryd became president and led the team to victory at NYC BigApps, and Tom became head of marketing before joining the Board of Directors. Harold Cooper became the organization's lead electrical engineer and Noelle Francois became the organization's head of community outreach.

The victory at BigApps set off a media blitz and soon Heat Seek had been featured in dozens of publications including Reuters and CNBC. The team incorporated as a nonprofit in November 2014 and launched the first phase of its pilot program after a successful Kickstarter campaign. The small scale test run was a success, and in June 2015 Noelle Francois became Heat Seek's Executive Director and first full-time employee, joined in November 2015 by William Jeffries as CTO. The team scaled the project up to 50+ buildings with the help of Blue Ridge Labs, an incubator for social entrepreneurs. Heat Seek graduated from Blue Ridge Labs and joined Beespace, an incubator for nonprofits, where it picked up its third employee and CPO Anthony Damelio.