93 ES Tranny Problem ???????

Ok.......I've been snowed in and it's FREEZING outside. I get the car started and put it in gear. After a while I come inside and warm up leaving the car running. Come back and when I shift into gear it is as if I'm not doing anything. No noises, you can't even feel it trying to go into gear. Shut it off....wait ten minutes or so and it works like a charm.....for about five minutes. REPEAT CYCLE. What the HELL??? Oh.....fluid levels are fine and I've NEVER NEVER had the slightest problem with the tranny? Can someone help?

Did you find the problem?

Not yet. Haven't made much effort lately.