I hope this is in the right area for this question, the question is, I am leveling up on destruction on Serana because I am mad at her, so it makes an easy ice spike at her! I am not for sure how long I play at a time, but it seems to where I've only been playing like for 3 hours, is there a time frame from where the xbox gets hot enough to where it shuts off? It may also be a bug also, she came in with the monk robes I gave her though in Fort Dawnguard, the only thing is that she bugs out every time I ask her to follow again, it's just the plain old, "do you need something?" That is kind of why I am using ice spike on her, I wasn't planning on using destruction that much, but I got mad at her and walla, she may not be able to be taken out of the game, but it is sure fun staggering her, any thoughts on the game freezing?

Serana not offering the option to be a follower -- From the UESP wiki:
Sometimes after completing the main questline for Dawnguard, while visiting a specific place (like Volkihar Courtyard), she will appear out of nowhere and act as if she were your follower even if she wasn't beforehand. If you dismiss her, however, you will never be able to recruit her again as the option "Come with me" will not appear. You will likely need to reload a save prior to this happening to fix this issue.

Freezing in the game just happens every so often when playing on the 360 console, nobody knows why for certain, but the following may reduce the frequency of it happening:

• Turn off ALL autosave options -- having them turned on can eventually lead to save game corruption
• Limit the number of game saves you have on your HDD to 10 or less (some people recommend 5 or less)-- backup others to an external storage device like a USB
• Weapons and shields do not clean up properly from enemies that you kill due to a bug -- take the dropped weapons and shields and place them back inside enemies' corpses. If you find shields and weapons lying around in odd (or unusual places), pick them up and sell them to a merchant so that they will be removed from the game's memory.