Thanks for your response.
Well, I went to my doctor who gave me information on MS, and said it could be MS, but that I should wait until more significant symptoms appear. I live in the UK, so the NHS will not stump up for an MRI until there is a good reason for it, ie. a real exacerbation. I have not had an exacerbation, all I have had are visual symptoms (including scotomas when I get hot) and this tingling sensation when I get hot. It's very strange. As I say, I can have a hot bath or a hot shower, but as soon as I'm experiencing a hot day, the symptoms appear... As it's cooling down now and entering autumn, I'll be surprised if I experience much more of it, and will probably begin to forget about it until next summer rolls around.
I have done a lot of research about MS, and at best I can only come to the conclusion that I have very unique benign MS symptoms which are atypical, and have so far avoided any of the more serious ones. No doctor on earth would diagnose me with any certainty as having MS with only these symptoms... so I'm stuck and have to wait until something else happens. I have had this for 2 years, although it has got worse over time.
I have tried to look for other answers, but none have come. I guess I could have lesions which are not MS, but still lesions on my brain?