Heat transfer in particulate systems is important to a vast away of industries, yet is poorly understood even in the simplest case - conduction through the solid phase. This is due in part to the stress and contact heterogeneities inherent to these systems. Heat conduction in a packet bed of cylinders is investigated both experimentally and computationally. A novel model is developed based on the Discrete Element Method, which not only sheets light on fundamental issues in heat conduction in particles, but also provides a valuable test bed for existing theories. By explicitly modeling individual particles within the hulk material, bed heterogeneities ave directly included and dynamic temperature distributions are obtained at the particle level. Comparison with experiments shows that this model yields a quantitatively accurate temperature field without the need for adjustable parameters or detailed microstructural information. This simple system may also provide insight into such phenomena as reactor hot spot formation and spontaneous combustion of bulk reactive materials.