How to Test Camp Oven Heat with a Simple Paper Test

Here's a way to determine the heat of an oven when using coals from a fire. Pre-heat the oven on a bed of coals. Place a piece of paper inside the oven to find out what heat the oven is at. The paper will change color according to the heat of the oven within a few moments.

Very hot oven 250 Dark brown
Hot oven 200 Light brown
Moderate oven 175 yellow
Slow oven 150 Crust
Too Bloody Hot ouch - help! Black & on fire! Call the brigade