Temperature Sensitivity


Are you temperature sensitive? 

In my experience the vast majority of pwMS are affected by changes in temperature; typically it is hot or cold temperature that triggers changes in central nerve conduction velocity that brings on old symptoms. One of my patients reports becoming paralysed if sits outdoors in the sunshine for as little as 30 minutes in the middle of summer. Other report worsening of their cognitive fatigue with relatively minor changes in temperature.  Women post-ovulation raise their body temperatures by about 0.5C; in some woman this enough to incapacitate them. I call this catamenial temperature-related fatigue and it often responds to non-steroidal anti-inflammatories and maybe the reason why aspirin has been shown to improve MS-related fatigue. 

This Korean study below is fascinating. They show that short-term exposure to wide diurnal temperature ranges (DTRs), which have become increasingly common as a result of climate change, is associated with an increased risk of visits to A&E (emergency departments). The was an ~9% change in the odds ratio per 1 °C increase in the diurnal temperature range. If this data is reproduced then it will have a major impact on how we manage patients with MS as global warming ramps up. I suspect the many exacerbations triggered by hot weather may prove to be pseudo-relapses. I suspect this may be the ideal use of serum neurofilament levels; to differentiate relapses from pseudorelapses. Sorting out this old problem may prevent unnecessary MRI scans and more importantly reduce the use of corticosteroids use for possible relapse.

Please be aware that it is not only the ambient temperature that is important, fever can also result in worsening of symptoms. With the COVID-10 pandemic in full swing, I suspect many more pwMS will be monitoring their temperatures as an indicator of infection. I wonder how many of you are doing this? And if yes was it advised by any HCP?  

Byun et al. Association between diurnal temperature range and emergency department visits for multiple sclerosis: A time-stratified case-crossover study. Sci Total Environ. 2020 Feb 25;720:137565. doi: 10.1016/j.scitotenv.2020.137565.

Although multiple sclerosis (MS) has been the leading cause of neurologically-induced disability in young adults, risk factors for the relapse and acute aggravation of MS remain unclear. A few studies have suggested a possible role of temperature changes on the relapse and acute aggravation of MS. We investigated the association between short-term exposure to wide diurnal temperature ranges (DTRs) and acute exacerbation of MS requiring an emergency department (ED) visit. A total of 1265 patients visited EDs for acute aggravation of MS as the primary disease in Seoul between 2008 and 2014 from the national emergency database. We conducted a conditional logistic regression analysis of the time-stratified case-crossover design to compare DTRs on the ED visit days for MS and those on control days matched according to the day of the week, month, and year. We examined possible associations with other temperature-related variables (ambient temperature, between-day temperature change, and sunlight hours). Short-term exposure to wide DTRs immediately increased the risk of ED visits for MS. Especially, 2-day average (lag0-1) DTR levels on the day of and one day prior to ED visits exhibited the strongest association (an 8.81% [95% CI: 3.46%-14.44%] change in the odds ratio per 1 °C increase in the DTR). Other temperature-related variables were not associated with MS aggravation. Our results suggest that exposure to wider DTR may increase the risk of acute exacerbation of MS. Given the increasing societal burden of MS and the increasing temperature variability due to climate change, further studies are required.

CoI: multiple

About the author

Prof G

Professor of Neurology, Barts & The London. MS & Preventive Neurology thinker, blogger, runner, vegetable gardener, husband, father, cook and wine & food lover.


  • Been measuring temperature for about two weeks having had odd headaches on and off (had first ocrevus infusions in the beginning of the year after diagnosis last fall). Staying home with mildly elevated temperature for the first time today as required by my employer’s pandemy planning.

    Neurologist suggested basic caution mid Feb but did not yet advise measuring fever.

  • I’ve been monitoring my own temperature for years. I know when I have an infection, but I’ve had some bad experiences in hospital. My normal temperature is low and if it rises to 36.8 I know I probably have an infection, if I don’t see or speak to a doctor that knows me I’m ignored and left to suffer. I’ve had lung cancer so I have the symptoms of the Coronavirus anyway and I just check my temperature everyday as a precaution, although I’ve always followed the hand washing guidelines. So if my temperature is 37, it probably means I need help. I’ve had out of hours doctors visit me at home and they have been brilliant, but in a hospital setting, it doesn’t work.

    • This is so frustrating. My temperature and pulse run low. My GP knows this. If I’m warmer than 37 something is going on. The practice nurse says not worried till it’s 38.2 for a while! By that time the MS is in free fall I had a lung infection in January and despite 3 lots of antibiotics still the MS was horrid Until I returned to my chilly self.

  • Another aspect of this Covid-19 and MS to watch is that the virus may (but has not yet been confirmed) be able to be spread by HVAC systems.
    As many people with MS might gravitate towards air conditioned spaces, this possibility of environmental exposure through air conditioning vents would be something to watch the emerging Covid-19 research for.

  • When I get hot I find it more difficult to move, though I know I will recover if I can get cool again. I have also noticed unexplained weakness before a cold develops days later. I put this down to a slight fever that I can hardly detect otherwise. So I have an early warning of any virus that gives a fever. Has anyone else noticed that?

  • I often feel feverish, with tiredness, body aches, stiffness, etc, but when I take my temperature it turns out to be below normal
    At such times I often have a paracetamol or aspirin tablet , which helps to make this fever type thing to away

    My theory is that this happens when the body is fighting a virus. Could that be true?

      • I have the same issue – when I feel sick (specifically, extra fatigued, cog fog and chills), my temperature is often running LOW vs high (between 96.0-96.9 F, whereas my normal morning temperature is around 97.9 and my normal daytime temperature is spot on “normal” around 98.6). I’ve never thought to try a fever reducer for it since I don’t actually have a fever, but I’ll have to try that next time.

        • Funny you say about low temperature, we went through about 5 digital thermometer thinking they were rubbishas MrsMouse had a very low temperature so we though the thermometer working, eventually we tried a hospial once and yep the temepeture was actually about 2 degrees centigrade lower, so when the temperature is normal it feels like a fever

  • I am on day 3 of moderate sore throat migrating down to chest and mild intermittent headaches. My temperature right now is 35.5 (under tongue). As I am usually cold and shivery even with extra layers I guess this could be normal for me but the thermometer is new so I have no history to compare. I will take the lack of fever as good news for now.

    • The thermometers are pretty useless, try breathing through you mouuth when putting under the tounge as the warm air from your lungs may give a better indication, I went through loads of them thinging I was a snale (cold blodded)

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