In this article the role of brown fat is explained and it contains references to many other studies:

• Patrick Seale and Mitchell A. Lazar. Brown Fat in Humans: Turning up the Heat on Obesity. Diabetes July 2009 vol. 58 no. 7 1482-1484.

The Dutch Study below nicely documents how alternating low room temperatures in the living room influences the amount of brown fat and the energy use. The authors describe two benefits of alternating the temperature; you feel cold less easily and it burns energy, which helps prevent obesity. 

• Anouk A.J.J. van der Lans, Joris Hoeks, Boudewijn Brans, Guy H.E.J. Vijgen, Mariëlle G.W. Visser, Maarten J. Vosselman, Jan Hansen, Johanna A. Jörgensen, Jun Wu, Felix M. Mottaghy, Patrick Schrauwen, and Wouter D. van Marken Lichtenbelt. Cold acclimation recruits human brown fat and increases nonshivering thermogenesis. J Clin Invest. 2013;123(8):3395-3403.