When looking at your daily average temperatures, ups and downs from one day to the next indicate the need for adrenal support, and if your average falls below 98.6, it's indicating the need for thyroid support.
There are a couple of ways to chart your temps, but the one I follow (and I believe this is per Dr. Rind), is to take your temp 3, 6, and 9 hours after waking. Average the three and chart.
I've spent the last 5 months charting my temps and upping adrenal and thyroid support, and I'm finally near stable. I use adrenal cortex extract, dessicated thyroid, and brazil nuts for selenium. I also take coconut oil, about 3 tablespoons daily.
My hope is that once I get further along in the Iodine protocol, I won't have as great a need for the dessicated thyroid, and that I can rely upon Iodine alone for the duration.