PPA (aka d,l norephedrine) is NOT thermogenic in humans in the way ephedrine is -- works great for this in rats. It does not increase norepinephrine levels, which is what mediated ephedrines effects. It also does not appear to bind to the beta 2 receptor to any significant degree. Alpha 1 agonists are vasoconstrictors, so they prevent heat from being released from the body, so they would raise body temperature and make you feel hot -- but this is quite different from causing calories to be wasted as heat.
However, it does have a couple of positive effects on fat loss above and beyond appetite suppression, and studies have shown subjects taking it to lose more weight than controls at an equal calorie level. One way is that it (and other alpha 1 agonists like synephrine) increases catecholamine induced thermogenesis. The second way I cannot tell because we will likely be using it in an upcoming product for this purpose.