The only CPUs without integrated graphics are the Phenom II and FX CPUs. I recommend avoiding the FX series since they pretty much have high power consumption. That leaves you with the Phenom II series.
Heat is directly correlated to power consumption. The higher the power consumption, the greater the heat generated. The following charts shows power consumption at different states for Intel's Sandy Bridge CPUs and AMD's FX and Phenom II series.
The Sandy Bridge CPUs consumes a little more power when idling (producing slightly more heat) compared to AMD's CPUs. However, once there is a load placed on the CPUs, the Sandy Bridge CPUs consumes less power than their AMD CPUs (and generates less heat).
The Ivy Bridge CPUs consumes less power than their Sandy Bridge counterparts (thus producing less heat). However,when OC'ed they do then to generate more heat than Sandy Bridge CPUs, but as long as they are not OC'ed this should not be the case. Unfortunately, only a single AMD FX-8150 is used as an AMD comparison.
Despite having an integrated graphic core Intel Sandy Bridge and Ivy Bridge CPUs tends to consume less power than their AMD counterparts, thus likely to generate less heat.