I don't know that there is anything *typical* about anything associated with this MySterious disease.
Heat erodes the signal that our circuitry can carry; this is already corrupted by the demyelination. How that plays out in symptoms depends on where your damage is at and how overheated you become.
Normally overheating is a temporary problem and a few hours after you cool off your body will have returned to what it knows as normal.
For me, my legs lose strength and my vision gets blurry. I never push it to the point of seeing how bad the heat can make me.
For many people with MS the heat is their enemy, but some people are not affected in this way. It can be the heat from allowing our body to get over heated or it can be from a raise of our body temperature when we are sick.
This is called Uthoffs phenomenon. I think I might have spelt it wrong but if you google it will answer most of your questions. Basically a raise in body temperature can temporarily worsen our symptoms.
I recently had a very bad incident where I was swimming in our pool which was heated like a warm bath tub, I was doing laps, it was a hot day so I was already hot, i come over all funny, and weak, I ended up having to lay on our couch until my body temp. cooled down, my legs were like jelly and I was unable to lift my arm to even brush my hair. It scared me as I was to weak to walk any distance, I thought I had perhaps had a stroke or a migraine, according to my neuro it was definitely Uhthoffs, after I cooled down i began to function normally again. I know now to be more careful, I have always had problems in the heat but not like that.
We're actually having a heat wave (WAY too early), so your question is very timely.
It seems you already know what heat does to you, and this summer is likely to have the same effects. You know you have to take precautions against them.
I agree with Lu that this can be a very individual thing.. There are those who don't have heat problems at all, though most MSers do, and most complain of a temporary worsening of symptoms. We have to hope it stays just temporary, because occasionally it doesn't. Bad news.
I suffer from a relatively new phenomenon, for me. I'm just very sensitive to rising temps, and feel overheated and miserable when I used to feel comfortable. One of my neighbors said today that it was so warm she'd have to open a window. Wow, I've had to run the AC full bore. Not at all sure if this is a direct MS thing.
I hope anyone here not accustomed to heat problems with MS will keep their antennae up and make adjustments as needed. This is one aspect that we can control, at least a little.
I am heat sensative too. I live in Phoenix, always has and always will.
anyhow, I have to stay really cool. if i get overheated and even when I dont mean to get hot , my body gets week, and I get nausious and sit by the toilet for a little bit. ater my body cools down, I feel fine.
This is time for a summary of why the heat can so devastate us, though certainly not all people with MS have this reaction.
Our bodies function by sending signals out to the body from the brain to tell it to do things, mostly to tell muscles to work. Sensory nerves run in the opposite direction telling the brain important stuff about the status of the body, like what is touching us and how it feels, where our limbs are, if our bladder is full, if we need more air - things like that. Within the brain and brainstem there are signals firing constantly to coordinate what we need to do and allowing us to understand within a microsecond how our body is doing - not to mention the brain doing thinking, emoting, planning etc. So the proper functioning of nerves is vital to the proper functioning of our bodies and mind.
A nerve that has damage somewhere along its protective myelin sheath is said to be demyelinated. The myelin serves to protect the nerve signal running in that nerve's fiber. When the myelin is damaged the signal is slowed down considerably. The signal still usually passes through and is not degraded, but retains its particular wave form. In places that are very badly damaged, the nerve signal may be completely lost. In this situation no signal arrives at all. For motor nerves this means paralysis of that muscle unit. For sensory nerves that means no message to the brain at all - total numbness, for example.
The nerve that has damaged myelin can be extremely sensitive to small increases in the heat of the body. This increase in heat can come from the outside as during a hot day, or it may be generated by the body itself like from a fever or the heated produced by exercising muscles. Just a fraction of a degree will cause the already slowed signal to slow even more, or it might completely block the signal from getting passed the area of demyelination at all, causing a complete nerve block.
WHAT SYMPTOMS ARE CHARACTERISTIC OF INCREASED HEAT IN THE BODY?
This is easy. The symptoms that any one person might suffer with increasing body heat are those same symptoms they already have, plus some. A person's symptoms, to a large degree correspond to the lesions they have in the CNS. Those are the areas of demyelination and also the lesions of neuron death. These may or may not be seen on the MRI, but they really are the lesions or areas of damage in the nervous system. So, if a person has weakened legs, those legs will get rubbery-er, weaker or even just collapse if the person gets hotter. The classic (and original) Uhthoff's Phenomenon is the loss of vision in someone with otpic neuritis. We now use the term for the reappearance of ANY symptom when you get hot.
So, you get more of what you already have when you get weaker.
But, there is another category of symptoms, too. If a nerve has been mildly damaged, it might not yet be causing symptoms. However, if you get too warm, that little bit of damage can now show up with a symptom you have never had. One day, early after my diagnosis, when I was just a silly girl, I got out of a long hot shower and noticed that my right foot was buzzing and tingling. I had never had that symptom before. At my next MS visit, I innocently asked my neuro if that signaled the next place I was going to have symptoms. My neuro answered, "STOP TAKING HOT SHOWERS!!!!"
In answer to the question, yes, it was one of the next spots to cause problems.
Also, an old symptom can show up. If you read the HP on "How MRIs Show Lesions in MS", I described the process of myelin repair and the fact that some lesions can disappear from the MRI. Even though they heal and disappear, the repaired myelin is no perfect and will always conduct the nerve signal a little slower. In the case of optic neuritis, this may show up as no visual symptoms, but a persistently abnormal VEP. The signal may be just fast enough to keep it under our radar. However, if you get overheated, that little bit of slowness to the signal may become severe enough for that old, symptom to reappear.
Ocassionally a spell of getting overheated will result in a permanent problem. More often it will do what it did to Julie (Sarahsmom). She luxuriated in a hottub after a gym workout. When she was done she was unable to get out of the tub and had to call for help. A stranger helped her out of the tub. She got sicker and sicker over the next three days and slipped into a severe relapse. It was more than 6 months before she was over that attack. So, even though getting overheated usually just results in what is called a pseudo-relapse or pseudo (false) exacerbation, it can sometimes be far more serious.
Rember we are talking only a fraction of a degree is enough to begin being symptomatic.
Not only do we need to take precautions while we are out in the heat, but also before. If you need to exercise they recommend pre-cooling with a cool shower and/or the wearing of a cooling vest. (I saw a marathoner precooling with such a vest before the Marathon at the Sidney Opympics. It's a known technique.) Invest in fans. If you can afford it invest in one of the fine-mist fans like they used at the Atlanta Olympcis and at amusement parks. That fine mist will lower the ambient temperature a full 20 degrees. Drink cold beverages.
Do investigate if your state offers rebates or credits for the electricity needed to run AC. This is available for MS in many places. Insist on A/c for the work place if it is hot. Sorry to you guys that work in foundrys. :((
Thanks for a very informative post on this, it has answered all my questions, I have never experienced weakness to the degree that I did that day in the pool and it terrified me. It was an extremely hot day, I was hot before I got in the pool, I had been riding my horse, I got in the pool and did laps for half an hour, the pool was heated to bath temp., I obviously raised my body temperature, once I cooled my symptoms went.
I was convinced I was either suffering a terrible migraine or a stroke, my left leg was jelly and my right was not much better but I have never had such profound weakness in my arm, it was worse than I have ever experienced before, this made me wonder if I am getting worse, so heat can make it worse than you have experienced, I still even questioned my neuro's diagnosis of Uhthoffs, but it was very frightening, I will never allow myself to get this hot again.
Thanks again Quix,
I appreciate you taking the time to give such helpful information.
thank Quix.. I find I get very tired, almost a sick feeling. My vision also goes off, blurry, double.. just all my symptoms seem to be worse..
I'll be looking for some cooling vests etc this summer.. I learnt from last year.
take care everyone