Low basal temperature is most commonly associated with thyroid underfunctioning (though is not entirely diagnostic of it). Dr. Broda Barnes (known for his pioneering work with thyroid issues) used basal temperature testing to determine whether individuals were hypothyroid or not, and he considered it to be more reliable than conventional blood work. The technique to acccurately determine basal temperature involves using an actual BASAL thermometer (widely available at any drug store) shaken down fully and placed by the bedside. Upon wakening, place the thermometer in the deepest part of your armpit for 10 minutes, resting quietly, then record the temp to a 10th of a degree. Repeat this over 3-10 days, then average the values. If the average is 97.8 or below, then low thyroid is suspected (also forms of pituitary and adrenal issues can be reflected by this also, as well as starvation). Women need to begin this on the 3rd day of their menstrual cycle. Men and post menopausal women can do this at any time. It is not 100% fully diagnostic, however. The American Endocrine Society concedes that conventional laboratory ranges used to evaluate TSH are currently far too broad to be meaningful to a major segment of the population and many individuals fall through the cracks of proper diagnosis, so to speak. The FUNCTIONAL range for TSH (as established by AES) is between 1.8 and 3. Anything over 3 and there is an underfunctioning thyroid. A follow-up TPO antibody test can determine whether this is autoimmune (Hashimoto's) related, or not (80% of all underfunctioning thyroid cases are Hashimoto's, according to AES).
This issue of low body temp--whether thyroid related or not (I have no idea, in your case) is also indirectly problematic from the standpoint of the liver. Liver enzymes are very temperature sensitive and may not function well or at all where temperatures are even slightly too low. This, in turn, gets in the way of detoxification processes. Low thyroid function also inhibits gastrin production which, in turn, can lead to hydrochloric acid insufficiency, which leads to poor protein digestion and mineral absorption which THEN leads to putrefied and otherwise poorly digested protein molecules creating irritation (and eventual leaky gut issues) in the GI tract and a more favorable environment for pathogens of all kinds....including yeasts. Protein here is not and never is the problem. Poor digestion is the problem. Hydrochloric acid supplementation can help immensely.
Yeasts are not entirely anaerobic and can adapt to a wide variety of conditions, making them very difficult to eradicate entirely. They can go dormant when the environment is unfavorable to their survival and they can even "morph" into fungus, growing into the small intestine lining and adding to hyper-permeability issues. Once the gates to the bloodstream are open, then, these critters (and anything else that follows suit) have a free superhighway to every place in the body your blood flows. It takes due diligence and often multiple interventions to effectively eradicate/manage yeast problems. Colon hydrotherapy can help flush out the GI tract and can perhaps help you get ahead a little more easily. There are products such as "ThreeLac" (you can google) that provide specialized probiotic organisms that solely target yeast cells (I dislike their use of canola oil--a hydrogenated/trans-fat product) in the formula, however. A product sold by "Enzymedica" called "Candidase" also works well for some. "Paradophilus" (again, google), now under the new (and less appealing) name of "Living Streams Probiotics" can, too, be a powerful adjunct here. Jim Humble actually recommends the "Paradophilus" product enthusiastically as an ideal adjunct to Miracle-Mineral-Supplement . Any of these, combined with Miracle-Mineral-Supplement should help a lot.
Having a lower than normal body temperature shpould not prevent you from producing a fever when needed, but can be problematic in the other manners mentioned here.