Before anything else, I'd start by looking at your hydration and in particular sodium supplementation in hot weather. Here's a rundown of current advise; scroll down to section 3.4 (hydration) and see how you stack up. (Potassium is not a substitute for sodium, so while eating bananas and drinking OJ is all good and commendable, it's more important to maintain your normal sodium levels. A low-sodium diet makes that easier since your normal level will be lower.)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6628334/