Ulaanbaatar, Mongolia is the coldest capital city in the world. During blistering, eightmonth winters, households meet their heating needs by burning coal in traditional stoves. As a result, the city also ranks as one of the most polluted urban areas on the planet. In 2009, XacBank, Mongolia’s largest microfinance institution (MFI), made a commitment to address this public health threat head-on. To date, XacBank has facilitated the ownership of over 80,000 efficient heating stoves and insulation blankets in Ulaanbaatar’s Ger District. XacBank’s evolving model combines innovative approaches to product development, quality assurance, consumer education, logistics and distribution. XacBank is also among the first MFIs to leverage carbon revenues to help sustain operations.