I know this is old but before anyone goes around thinking you can take DNP and run around during the winter and have any significant fat loss, you need to read this publication. Basically, if you lower the ambient temperature below thermoneutrality (37 degrees C for humans) the body adjusts and compensates by reducing brown adipose tissue activity. This combats fat loss and results in very little if any net fat loss.
Goldgof, M., Xiao, C., Chanturiya, T., Jou, W., Gavrilova, O., & Reitman, M. L. (2014). The chemical uncoupler 2,4-dinitrophenol (DNP) protects against diet-induced obesity and improves energy homeostasis in mice at thermoneutrality. The Journal of Biological Chemistry, 289(28), 19341–19350. doi:10.1074/jbc.M114.568204
Goldgof, M., Xiao, C., Chanturiya, T., Jou, W., Gavrilova, O., & Reitman, M. L. (2014). The chemical uncoupler 2,4-dinitrophenol (DNP) protects against diet-induced obesity and improves energy homeostasis in mice at thermoneutrality. The Journal of Biological Chemistry, 289(28), 19341–19350. doi:10.1074/jbc.M114.568204