One favorite site of mine, Tuberose, has some excellent info; going in depth.. The info is overwhelming, so I start with the body temp, as one of the reasons I got healthier is because my temperature raised from 36ish to 37ish after iodine; almost one degree Celcius made a big difference!

"Core Body Temperature

Much emphasis in conventional medicine is usually placed upon feverish conditions; however, a low body temperature can be a much more sinister condition. Where a fever can be viewed as an active developmental and corrective process of the healthy body, a low body temperature can never be viewed as a normal or healthy condition, nor is it a mechanism for a learning or developmental process in the body.

A low body temperature creates a happy home for microorganisms and chronic infections, and is a sign of degeneration and gradual cellular death.

Low body temperature is the plague of the 21st century. People with low body temperature have a weak reaction to even the most ideal medicines and therapies. As the body’s core temperature decreases, all cellular energy also decreases. The cooperative and collective intelligence of the human organism is short-circuited as the body temperature cools. As a result, all cellular functions decrease. There is a decrease in the production of all hormones, neurotransmitters, and other body chemicals, necessary for normal healthy regulation.

Viruses prefer and promote a cold environment and replicate at a much more rapid rate when the body is cold. Viruses are killed and further replication is impeded by maintaining a warm body. Some bacteria, such as Lyme spirochetes, also prefer and promote a cold environment and can remain in a chronic state as long as their cold environment is maintained.

The ultimate body coldness is seen in death. In death, the blood and lymph fluids of the body solidify and the body becomes stiff and cold. In the same way, in many chronic cold illnesses such as cancer, Lyme disease, fibromyalgia, chronic fatigue, diabetes, and heart disease, we see that the body becomes progressively colder. As the body cools, the electrical oscillations of the fluids slow down and there is a shift in the body’s polarity which promotes infectious microbes and cancer.

When the core temperature of the body is cold, every organ, gland, and tissue is affected and becomes hypofunctional or may even become hyper, as in the case of hyperthyroidism, in a last-ditch effort to compensate for the hypothermic condition of the body.

A variety of hormonal symptoms can exist in hypothyroidism. Perhaps the most common is a loss of libido (sexual drive) in men and menstrual abnormalities in women. Women with mild hypothyroidism have prolonged and heavy menstrual bleeding, with a shorter menstrual cycle. Every type of disturbance may be seen from amenorrhea (no period), to profuse menorrhagia (heavy bleeding), especially at menopause. Infertility may also be a problem. If the hypothyroid woman does become pregnant, miscarriages, premature deliveries, and stillbirths are common. Rarely does a pregnancy terminate in normal labor and delivery in the overtly hypothyroid woman. Muscle weakness and joint stiffness are predominate features of hypothyroidism. Some individuals with hypothyroidism may also experience muscle and joint pain, and tenderness. Dry, rough skin covered with fine superficial scales is seen in most hypothyroid individuals while the hair is course, dry, and brittle. Hair loss can be quite severe. The nails become thin and brittle and typically show transverse grooves. The brain appears to be quite sensitive to low levels of thyroid hormone. Depression along with weakness and fatigue are usually the first symptoms of hypothyroidism. Later, the hypothyroid individual will have difficulty concentrating and be extremely forgetful.

Frequently, blood tests of hormone levels are normal, but basal body temperature is abnormally low. Shortness of breath, constipation, and impaired kidney function are some of the other common features of hypothyroidism. This condition is often associated with Wilson's syndrome, physical and emotional stress, and Hashimoto's disease. Fortunately, cretinism and myxedema, the extreme forms of hypothyroidism, are relatively rare. Occipital-cervical aching with radiation to the shoulders or intrascapular area is common. Also rheumatoid pains may occur in various joints and parts of the body without evidence of inflammation. Blood cholesterol is often elevated. If the cholesterol is elevated, it is a presumptive diagnosis of hypothyroidism. All of these symptoms have been treated with thyroid extract and Iodine supplementation successfully. The only reliable diagnostic tests worth doing are the basal metabolic rate, saliva test, and serum cholesterol.
http://www.tuberose.com/Thyroid.html