For anyone interested in monitoring how much heat it actually takes to stop stuff here's some math:
We'll use as our point of comparison, a coke can full of water (250 mL).
Since you have been holding it in your hand for a long time, the water is at body temperature (37 C)
The specific heat of water is 4.186 J/g per C, so it would take around 1046.5 Joules to heat up your can of water 1 C.
So how much energy is ~1000 Joules you ask?
A 9mm pistol bullet is around 500J, a big pistol bullet (~.44 magnum) is around 1000 joules, a rifle bullet (7.62 Soviet) is around 2000 joules.
So if our heat based shield is based off taking the energy out of the bullets (so they come to a complete stop in mid-air) and just fall down) and transferring that energy into our coke can.
So assuming our heat shield is 100% efficient, and some bad buy empties all 30 rounds of his AK into our heat shield, your coke can full of water goes to ~97 C, not even boiling yet. But certainly hot enough to burn you if you holding it. (Somewhere around 45-50 C is hot enough to scald your skin). A magazine full of fire from a pistol (15 rounds of 9mm) is only enough to raise the temp of our coke can is barely enough heat to raise it from body temperature to hot enough to scald you.
So what do we learn from this? Enchanted cans of Coke that provide you a fire based defensive shield that stops bullets can totally be tapped from cool and refreshing drink afterwards, as long as you don't get shot too much.