Again,  necessity is the mother of all invention and using what is on hand is key. Now I would never think to keep shelving brackets on hand but this is quite the ingenious idea and it cuts down on the amount of stuff you have to carry with you. With steel having a melting point of 1370 degrees and a typical (small)  campfire reaching only about 500 there should be enough wiggle room for the brackets to withstand the heat.

Like any fire, you will want to gauge how hot it is by the color but a small fire (from my experience) will not go much over 500 which is perfect for this situation.

Have you ever used steel brackets in this manner before? If not what sort of strange items have you used in this manner? Let us know in the comments below.