My original reply was lost in electronic never-never land, so I am trying again.
One thing that I have found that really helps in addition to the suggestions that you have gotten above is a baby fan that hangs on a string around my neck. I have two kinds. One of them is labelled as O2-cool and is a 3 X 5 X 0.5 inch rectangle with the direction out the upward (3 in) part. It is quiet and has AAA batteries so it can be used when doing things. The other looks like a mushroom. I will look for the manufactures and post this later. I got both of them at Walgreen’s pharmacy store and they were each about 4-6 US dollars (pretty inexpensive).
Another suggestion is to plan outdoor activities in the early am or late evening before dark. A third is to build in rest times. If I overheat, I have to now stop totally for 15 minutes or so. Planning outdoor activies in little pieces or having a chair and book available (as well as ice water) really help.
WithHope for a cure of these diseases