Cold weather start up-idled really high, quit running, won't start now

Truck had been sitting in cold weather (last winter) and not being driven. Started it up and it idled really high (screaming). It wouldn't idle down, and before I could shut it off, it conked- quit running. Now it won't start at all. It will crank over but won't start. (I learned the really high idling could of been because it does have a air leak in valve cover, combined with cold weather)? Any ideas why it won't start and run? Thank you!