Maybe it’s the same thing I recently had. After running a half marathon in April this year and cycling another 20km from and to the course, I also had some weird muscle cramps when finally taking a rest. It was almost like something was crawling under my skin. My muscles felt like they were cramping together and releasing very quickly and very locally in tiny spots all over my calves. It was such a surreal feeling. Kinda creepy and weird, but at the same time also kinda nice and satisfying.
Block out the heat and sun during the day. Have everything open during the night, with a tactical fan placed wherever it helps the most.
But this only really helps the first few days. After that it’s down to accepting the situation and being so tired that you fall asleep anyway.