For the sake of clarity, I chose to tackle this gentleman's question from a purely physical aspect. Humans and other mammals function best at a core body temperature of 37° C. If we elevate this temperature to beyond 42° C, the proteins, which run our bodily functions, begin to fall apart. Body temperature is controlled through a thermoregulatory system. Problems anywhere in this system can make you feel cold. Temperature sensors in our skin send signals to the hypothalamic area of the brain where processing occurs. Our body temperature does have a cyclical variation of about 1° C reaching a low point while we sleep. To elevate body temperature, the system will send nerve signals to the pituitary gland and release messengers into the blood. These messengers will cause immediate responses in the thyroid, adrenals and muscles. The result is a combination of actions. Blood vessels will constrict in the peripheral regions which shunt warm blood into the torso. Epinephrine type substances from the adrenals will increase our basal metabolism which generates heat. Secondary systems such as shivering can be activated if necessary. This system is sensitive to internal sex hormones as most women undergoing menopause soon discover.
Too much heat loss can also result in feeling cold. We lose heat in four ways. Radiation is the emission of infrared energy and accounts for most of the heat loss. Heat can also be conducted or transferred directly to objects next to the skin or lost by air moving over the skin, which is termed convection. Perspiration involves the conversion of liquid to vapor and requires energy, hence there is loss of heat. Increasing any of these causes a cold feeling.
When there are problems in the thermoregulatory system, people can become cold sensitive. They may experience a feeling of being chilled, cold sweats or even fever. Cold hands and feet don't really count. The commonest causes are genetic variations and aging. With age, the system is not as sharp and some people simply lose body mass. Diseases which affect the system are another reason. For example, pituitary tumors in the brain could interfere with the first part of the system. Persons with poorly functioning thyroid glands also seem to have trouble staying warm. Addison's Disease affects the adrenals and reduces the output of vital hormones, which will impair the metabolic response to cold. Even mood disorders and depression can influence the loop to produce a constant chilled feeling. Blood circulates heat around our body. Blood disorders such as anemia can impair this ability. Some people suffer from Raynaud's Phenomenon, a disorder of small vessels in our toes and fingers where cold triggers a spasm. The loss of blood flow causes a painful burning sensation, and skin color changes to white or blue. Anorexia can produce cold intolerance by simply losing a critical amount of insulating body mass. The same applies to other wasting diseases such as cancer and AIDS. Herbs and other drugs such as alcohol can also influence the system. Alcohol produces that "warm" feeling by allowing warm blood to flow to your periphery, which is why it is only temporary.
What all this means is that in some cases there is a ready solution to help your cold wife. It may take some time and involve a complete medical examination. Unfortunately, if your wife not only feels cold, but also acts cold and talks cold, then it will require a great deal more than this column to assist you. I would suggest flowers and champagne for starters, followed by that elusive elixir called romance!
● Conversion Tables: Degrees Celsius to Degrees Fahrenheit
● Degrees Fahrenheit to Degrees Celsius
● Temperature of a Healthy Human (Body Temperature)
● The Cold Body Page: Chronic Sub-Clinical Hypothermia and Wilson's Syndrome
● Why do we feel cold when we have a fever? from Ask a Scientist (slow loading)
● Symptom: Chills: Excessive feeling of coldness
● Possible Causes of Symptom: Chills from WrongDiagnosis.com
● Hypothermia is a decrease in body temperature to 94° F or lower, from Merck Manual of Health & Aging.