A method of performing an ablation procedure includes the steps of inserting an antenna assembly into tissue and supplying energy thereto for application to tissue. The method also includes the step of causing contact between a first material and at least one other material disposed within the antenna assembly to thermally regulate the antenna assembly. According to another embodiment, an ablation system includes an energy delivery assembly. A first chamber is defined within the energy delivery assembly and is configured to hold a first chemical. Another chamber is defined within the energy delivery assembly and is configured to hold at least one other chemical. The first chamber and the other chamber are configured to selectively and fluidly communicate with each other to cause contact between the first chemical and the at least one other chemical to cause an endothermic reaction and/or an exothermic reaction.