Well, every human's body temperature varies over the course of the day and night, and all women who have ovulatory menstrual cycles will experience a substantial rise in temperature for the second half of their cycle, which makes this question tricky to answer in some ways. So if anyone is panicking because of their temperature fluctuating, don't! But I think anyone who has spent enough quality time with a thermometer will have sussed out whether they're running particularly hot or cold by now. I take my basal body temperature at 8 am every day in order to track my cycles, and my temperature falls within the classic ranges that are given for Fertility Awareness Method charting, so I've ticked "normal" even though it will only cover my temperature at some parts of the day and for some parts of my menstrual cycle.
I've started getting gallstone attacks recently, and the first one was in the middle of the night and involved agonising abdominal pain and being freezing cold despite having every quilt and blanket in the place piled on top of me. My temperature came out as 34.5 five minute before the emergency doctor arrived, which even for the middle of the night is low. He stuck a thermometer in my ear and airily told me it was normal. A trainee nurse friend of mine, who exclaimed, "But that's seriously hypothermic!" when I told her what my temp had been, reckoned that he didn't even glance at the thermometer. He didn't bother to examine my abdomen properly either, so I'm guessing that he heard that I have ME, saw that I was sitting under a yellow bulb (darkness therapy - I was too bewildered from pain to realise that being kept awake by blue light really wasn't a factor by now), and assumed that I was just a hypochondriac. He did at least give me useful meds for the pain, but I should have known that "it's probably just a virus" is a bad sign, and of course I didn't get the diagnosis of gallstones until my next attack, which thankfully was during the day and got me to a more competant doctor.
I've also found my temps have dropped due to dieting. I started dieting 8 months ago, at a slow and sensible pace of course, but did find that I was suddenly feeling cold all the time, and my temps dropped noticeably. It turns out that it's very common in dieters. Thankfully taking two 500mg ginger capsules got my temps back up to my usual range and stopped the shivering. I went down to one capsule after a while, I'm broke, but I should probably go back up to two now that the weather is getting cold again. I'm frustratingly close to finishing losing weight, and on the one hand I want it over and done with (I want to be able to buy some sweaters that actually fit, for starters), but on the other hand I've decided to go with slower weight loss for the last stretch in order not to stress my body out too much.