It heats up really fast in the winter ! But it also really heats up fast in the summer ! It will shoot up in stop and go traffic, rock crawling, off road.Thank you all for your responses. I'm also learning how to use a forum so I apologize if I'm not doing it right!
My JK has a manual transmission. Stumblinhorse: it's doing what you have described. I love how fast it heats up... hopefully it's the same when it gets really cold.