At 5pm its 99 degrees here in the Phila suburbs.
It was already quite hot this morning at 9 am. in the 90's
I still say you can't slow down. you still have to make it to the next water source and you may actually have to speed up to make it, not slow down.
You can't take it easy either. You have the weight of extra water, maybe a gallon or more in your pack and you still have to hike up hill with all that weight.
nite time hiking has its own dangers.
All the things you suggest will help some but it will not solve the problem of excessive heat.
The heat will exhaust you. especially after 3 days of it.
The heat is not just uncomfortable, its dangerous. that's no BS either.
Panzer