Won't Idle Cold

I have a 1995 GMC truck 350 ci. and this last week when I first start it won't idle.After temp gets up everything is OK.This week temps at 30 deg.Also noticed temp.gauge not moving much.
Thanks for any suggestions. RAC

check the idle air control valve on the throttle body. this IAC valve lets extra air into the engine on cold startsas well as controls idle speed. you might be able to just get away with taking it out and cleaning all the carbon build up off it.