Sun = Heat = Fatigue = MS Symptoms Worse But WHY ? +

So as we all know and its well document that the warm weather and heat can make our symptoms worse.

However , call me Doppy but I just dont know why ?

I can remember when I was first diagnosed talking to my sister and cousin about their MS and how the heat effects them, but at that time the heat didn’t effect me at all, I thought they were over exaggerating things, in fact I was still going to places like Tenerife in the summer for holidays !

That was 6 years ago !

6 years later and things are vastly different, the heat or muggy warm days absolutely wipe me out, I can barely lift my legs to climb the stairs, I almost shuffle around the house dragging my feet, yet on these types of days I don’t actually feel within myself that much warmer than a normal day, perhaps a little bit warmer but nothing drastic, I certainly don’t . feel like I’ve been sitting in a sauna for hours getting all hot and sweaty.

So why does the heat make our symptoms worse ?

What is actually going on with the nervous system ?

Does it only take slight rise in body temp to kick things off ?

I’m the same, it’s only a few years ago I could walk for hours on holidays to Spain etc but now I overheat at the slightest increase in heat. It feels as if my blood is boiling under my skin and am wiped out. Even sitting in the living room with the sun shining in the window can set me off.

mind you the same happens when there is a dip in temperature. I think my body temperature is faulty.

My family just look at me in bewilderment when this happens.

my son-in-law is applying for jobs in Saudi Arabia, goodness knows how I’m going to cope going over there for holidays.

Mags xx

Totally agree. If I’m outside and the temperature has dropped a bit and I get just a bit of a shiver my legs almost lock up, I tend to walk almost like a robot. Then on the opposite end of the scale if I get just a bit warm and muggy my legs are like lead, no lift or or strength at all. Its like the 2 opposite extremes kick things off.


I hate heat and humidity it exacerbates my symptoms. air conditioning unit will be on today lol. I bought it for 80.00 off studio it is small but works a treat.

I sort of had it explained to me about why heat affects us. But the link below explains it in English lol…

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there is some mechanism that regulates the body temperature in healthy people.

some kind of internal thermostat.

mine is most definitely on the blink.

the first two days of this fine weather were glorious as there was a cool breeze.

however now it’s gone muggy.

Thanks for the link C C I just thought I was being a wuss, and it turns out I actually have a reason for feeling worse in humid heat. M

“Internal Thermostat” eh !!!

Time to call the MS plumber me thinks.

If only it were that bloody easy angry

This describes me exactly - my husband has finally got used to this but others look at me like I’m mad

I hate it when the weather forecaster says how warm it will be with a huge smile and isn’t it great - I just want to shout at the TV not everybody loves the hot weather

Excellent link CC. I did also find one that spoke about some people with MS being effect by temperature in both directions, cold as-well as hot.

I definitely fall into that category.

Too cold and I walk like C-3PO from Star Wars, too hot and I’ve got nothing in me, no strength, legs wont lift at all, just a slow awkward shuffle, and my hands feels like I’m trying use them with mittens on. Nightmare.

Uhthoff syndrome where an increase in temperature cause problems for pwms was first mentioned over a 100 years ago. Hasn’t any progress been made since then in finding out why heat is a problem for us?

Ive asked this question at my MS clinic and all I get back is “try to stay cool” ! No really, who would of thought eh !!!

Bit obvious, but haven’t heard any different.

“Temperature sensitivity could be caused a number of ways. Extremes of heat and cold may affect the speed at which nerve impulses can travel along your nerves, particularly where there has been demyelination or nerve damage. Alternatively, MS may have caused a lesion in the part of the brain that controls or responds to body temperature. Your brain may not trigger sweating or shivering responses that keep your body at the best temperature for comfort.”

Would this be the same for spinal lesions ? My last scan shows no brain lesions.

My understanding is that nerve signals are slower when transmitting over areas of damage and this gets considerably worse when the temperature goes up. If you need more detail then the Barts Blog is probably a good place to look and there have been many threads on the subject over the years.

I hope you find the answers you seek.