Print Warped

[arktape 2]

I started this print Friday afternoon and it was done by Monday morning. It was supposed to be a U channel. At some point either in cooling down or printing it warped. Why did this happen? What can I do to fix it? I was printing four at the same time. Approximately 12" x 2" x 3.5", UMS5 Pro, UM PETG, 0.8 mm nozzle, Standard Cura settings, either 20 or 100% infill.  

[Smithy 1,146]

Is the shown orientation on the picture the print orientation? Then it "warped" sideways, which is not really warping. In that case I would say it was too hot inside the printer and the model deformed during the print. You can try to open the front door that it don't get too hot inside.

[arktape 2]

Okay, I will try that next time, thanks!