With a temperature that low, this is really something that needs to be evaluated by a physician so that a full workup can be done to evaluate the cause. The list of possible specific causes is quite lengthy, but that can be narrowed down systematically by a doctor. In short, your husband needs medical attention. Please feel free to continue posting here and/or on other related communities. As SurgiMenopause mentioned, you may be interested in posting on the Dysautonomia Community forum as well, as the dizziness and pre-syncope (almost fainting) are common to patients in that community and the hypothermia can be mediated by the autonomic nervous system.
Hmmm... In some people (especially older patients) hypothermia is actually the same analogous to a fever and indicates a underlying infection. The concurrent dizziness and hypothermia warrents medical attention as it may be easily treatable if it is due to an abscess or other infectious processes/ autoimmune process. It could also be due to side-effects of certain medications like anti-cholinergics or NSAIDS. I would highly recommend seeking medical advice.
The hypothalamus gland regulates temperature. Have you tried taking his blood pressure when he feels dizzy & is this while lying down he feels this way? I am thinking this sounds like he may have a dysfunction of his autonomic nervous system (not a dr, & he needs to be evaluated by proper specialists). Please take a look at the dysautonomia forum here on medhelp & try your post there as well? Here's a link:
http://www.medhelp.org/forums/Dysautonomia-Autonomic-Dysfunction/show/266
do he drink tea? if you get some ginger root make some ginger tea for him grater it, and add some peppermint tea bags it should heat him up..before he goes to bed he should wear socks too when hes going to bed.