OK first off this isn't one of my clones this is my 31 day old northern. Just thought I would clear that up first. Now that you mention heat though it got me thinking. After I transplanted I had to adjust the height of the light and the temp went up to 84(which they aren't used to) for a breif point and it was only after that I noticed the twisting. It is on the top leaf after all(forgot to mention that). I'll go check on them and get back to you guys(very hectic morning). Thanks