is there a clutch switch too

2004 3500 6 speed. This morning the temp was -6 in Iowa and when I started my truck it went to fast idol like normal but fell out of it abought 45 seconds after starting. I know when I step on the break peddle it will dropp out of high idol but will it dropp out stepping on the clutch? I have break lights but no cruise control. So is there a clutch switch and if so whitch one is the most likley problem?