Is there any disease that causes the body to totally lose the ability to regulate its temp? If so, how would something like that be treated? Is the person a goner?
I am not a biologist, but my understanding is that body temperature in warm-blooded organisms is controlled at the cellular level. A disease that caused a loss of ability to regulate temperature then would have to act all across the body, and in a drastic way. This would almost certainly be lethal, and quickly.
Not to mention it seems extremely unlikely that such a disease would propagate itself (given the assumed lethality, and the fact that it would most likely be a genetic condition).
I’d be very interested to be corrected, or backed up here, so someone that knows a bit, please help.
Actually I think that you body temp is controled by you brain because your body temp heats up when you get ill. (thus to make it uncomfortable for the germ) so you might need brain damage to turn cold blooded.
Yes, some people cannot regulate their body temperature in a normal way. This is called poikilothermia. Usually, this rare condition results from damage to the hypothalamus (a deeply situated part of the brain that controls vegetative things such as appetite, sex drive, thirst, temperature regulation, etc.). Damage to the hypothalamus is most often due to tumors in the area.
In addition to people with hypothalamic disease, sometimes people with spinal cord problems also have trouble regulating their temperature for two reasons - i) they can’t readily put on or take off an extra blanket if they’re cold or hot and ii) their blood vessels aren’t getting the right signals from the spinal cord to retain or give off heat.
So long as people are aware of their poikilothermia, and take proper precautions, they should not be “goners”.
Slightly OT,
What would cause consistent, abnormally low temperatures? I’ve known one or two people with “normal” temperatures around 95.5 to 96 degress F. Not due to illness, or error in the thermometer.
Well, despite the so-called normal level of 98.6 (37 C), there is a range of normal. Oral temperature is normal between 96.5 and 99. Axillary (armpit) and tympanic membrane (ear) temperature can be 0.5 degrees less.
So, normal temperature depends on where it’s taken and when it’s taken (lower in early AM). And, temperature goes up after physical exertion. Note also that oral temperature can be (spuriously) low in mouth breathers.
Rarely, an underactive thyroid can lead to chronically and abnormally low body temperature. Likewise, anorexia nervosa and starvation.
Thanks KarlGauss, eating disorders sound right to me based on what I know of the people involved. We eliminated as many factors as possible before taking the temps - laying down for a minute or two before taking a reading, breathing through the nose, no cold or warm beverages immediately prior. All these precautions, because I simply didn’t beleive it was anything other than systematic error. 
I’m like this. I run a temp just over 95. Everytime I’ve had my temp taken at the ER the little alarms go off on the machine. New doctors also tend to retake my temp several times instead of just taking my word for it that it’s normal for me.