As others have said but its good to repeat you need to eat/drink to replace the minerals that have been sweated.
Before we lived at our place I would work up to 12 hours in the summer time. I forced myself to eat Cliff and Luna bars though I was not hungry. Drinking water was not hard.

The energy bars put the missing minerals back into me.
I don't work those hours any more now that the house is built and we live on the land.

I don't eat the energy bars but if it is hot and humid I will make up a "sport drink" to replace the minerals. I have noticed if I DONT drink the sports drink I will get cramps. If I do drink the stuff I don't get cramps are very few with less intensity.
This past weekend I was going to work on Saturday. Got up early and cut a hair cut at 0730. Its an old fashioned country barber shop.



Good people but hearing about the barbers prostate problems and how to wee was shall we say "interesting."


He is 83 years old and has been cutting hair in the county for 50 years. He knows where the skeletons have buried the skeletons.
Anyhow, got home it was cool but the humidity was in the 90s. The chores that need to get done have been done. The grass can grow another week.

Too danged hot for me.
I have also found that keeping the sun off your neck can keep you cool. If that sun heats up your neck it can take you down quick.
Later,
Dan