Wondering if anyone has kids who overheat easily and if so, what you do to manage and any reasons you've discovered for why.

We live in northern VA (hot and humid summers). My almost 8 year old was prone to overheating since she was about 5 or so, which typically resulted from her major FOMO and going too hard at whatever activity she's involved in. Before camp 2 years ago, we taught her to pay extra attention to her body when she's exercising or playing, and to take breaks, cool down and drink water. Last year she didn't do camp but we spent a fair amount of our summer outside hiking and doing other activities and she generally seemed fine. This summer she will be heading back to camp and I'm getting nervous because in the past few weeks I've noticed that she seems to wilt very easily even in weather that I don't consider that hot (high 70s/low 80s). We go to the playground after school every day and she'll play fairly gently (monkey bars, some light climbing, etc.) for 15 minutes or so before becoming flushed and sweaty and will say that she feels tired. After some water and sitting she'll get back into it, but it seems like it's more acute than before. I think some of it can be psychological - I notice this happens more often when there aren't other kids to play with or when she's not in an active game of some kind - but that's not exclusively the case. I'm taking her for some bloodwork that our ped recommended we do anyway and will see if anything turns up but wondering if anyone's had this experience with their kids and if there's anything I should watch out for. She's otherwise perfectly healthy, great eater, great student, no medical issues, sleeps well, not on meds, etc.