Hi Lara,
We do often hear reports of thal minors experiencing dehydration so there may be a connection to thal. I'm not thal but have suffered from dehydration in hot weather and I am quite experienced with it. One of the worst things is that when you are dehydrated, it clouds the mind and you don't quickly recognize the problem. I tend to feel vague and can't even figure out what is wrong at first, which is completely out of character for me. Once I learned to recognize this while experiencing it, I found it much easier to deal with. The formula you found is a basic electrolyte formula and should help. It is similar to what is in Gatorade. In my own case, making sure I take some salt or salty foods with water is all that is needed, but adding the other minerals may help, so I would say definitely try it for awhile, since water alone cannot replace the minerals lost due to the heat. He should never go long periods without water. Even in school, a water bottle may be necessary, but this should be cleared with the teachers in advance and they should be made to realize it is a medical issue, so the exception to bring a water bottle to school should be made. And yes, you will constantly read that thal minor has no symptoms, but that is just wrong and it is no longer excusable for doctors to brush it off as nothing. An employee of mine who is thal minor was made to spend a year in bed at age 5 because of thalassemia and at one point the recommendation to remove his spleen was made, although not carried out. This was back in the 1950's so I have a problem with the medical profession continuing to ignore thal minor. Many thal minors do have significant symptoms. proper nutrition is essential to help combat the effects of thal minor. Please familiarize yourself with the recommendations in the Diet, Nutrition and Supplements board of this site.