The epoxy curing process is exothermic, so if you mix up enough in a confined container (I use the transluscent Fuji film canisters), it'll heat itself up pretty good. A strong word of caution here, though: believe it or not, it can heat up too much. Heat accelerate the curing process and the whole thing feed on itself and can quickly run away. When I used to mix up a whole canister full for fibreglassing, I had to remember to work pretty quick to get it ready to pour out. More than once I didn't work fast enough and ended up having to rush the smoking canister outside of the house.

Two more thoughts:

1. Burning epoxy fume is toxic.

2. Before you start, think of a place outside where you might not care to have a puddle of melted goo.