I own a ford windstar and my transmission seems to get stuck in low gear after it gets hot, normally I can drive around for quite some time without a problem. Last week I was stuck in traffic for an hour and when I started to drive again it would not shift out of low gear, and the rpms jumped a lot higher than normal, I'm not very mechanically inclined and I would like to know if there is any help or does anybody know what the problem is.thanks.

First off check the basics start by ensuring the trans fluid level is all right.
I'm not a trans expert but would say one possibility is a faulty speed sensor
As it determines shift points for the trans. In order to locate it you might
Have to buy a repair manual such as a Haynes book for your car.It is located
Somewhere on the transmission housing.Yet another possibility is if your trans filter {IF equiped} or screen is is too dirty/clogged this too could be the cause.