Question

Do people with ME have a low body temperature? My body temperature always seems to be slightly below normal when I check it with a thermometer and I’ve seen this being discussed on internet discussion forums. I’m also starting to feel the cold more than I used to do.

Answer

It’s worth pointing out that problems with temperature control are a very common problem in ME/CFS. Among the symptoms that people commonly report is being far more sensitive to changes in external temperatures than they were before being ill. This can result in feeing worse in hot weather, and being more fatigued after having a hot bath for example. At the other end of the spectrum it can involve suffering from cold hands and feet during cold weather. These temperature control problems are probably caused by a malfunction in a tiny gland in the brain called the hypothalamus – which acts as a sort of thermostat when it comes to regulating appetite, sleep and temperature.

It can also happen regardless of external temperatures. This might be something pertinent to ME/CFS or it could be because 75% of those with ME/CFS are women. Women have a much more sensitive vascular (blood vessel) response to the cold or to a sudden change in temperature that can restrict the flow of blood. The hormone oestrogen contributes to this process. Women also tend to be better insulated than men, meaning their skin temperatures can be lower.

But, to answer your actual question, low body temperature is sometimes reported by people with ME/CFS. However, the only research evidence available concluded that there was no evidence for low or high body temperature in ME/CFS (see below). Low body temperature is not listed as a characteristic or diagnostic feature of ME/CFS, but it is a recognised symptom of low thyroid function/hypothyroidism. As this is a condition which causes fatigue and cognitive dysfunction, a simple blood test for thyroid function should always be checked if you do have a low body temperature.

Research:

Background: Subjects with chronic fatigue syndrome (CFS) frequently report symptoms of subnormal body temperature and low-grade fever. We conducted a study to determine whether CFS subjects manifest any abnormality of core body temperature (CBT) that might help explain their fatigue.

Methods: Continuous 24-hour recordings of CBT measured every 5 min were performed in 7 subjects meeting the Centers for Disease Control definition of CFS. Three additional groups were studied: normal controls, subjects with seasonal allergy, and subjects with major depression.

Conclusions: Subjects with CFS have normal CBT despite frequent self-reports of subnormal body temperature and low-grade fever.

Core body temperature is normal in chronic fatigue syndrome | February 1998

More information

• The ME Association has detailed information about Cold Hands and Feet and abnormal temperature regulation available to download from the website shop.