Something has been puzzling me about our ancient ancestors, say...

Something has been puzzling me about our ancient ancestors, say -20k years ago and beyond into the ever streaming mists of time.
I know from personal experience, and equipped with a sufficiency of modern time saving equipment, just how much time and effort is required to gather enough firewood to keep me warm in a short winter.
Now, take away those tools and give me a stone axe and I would be, in the words of the Bard, rooted.

Given that felling all but the smallest trees would be too time-consuming when you've also got to hunt, that leaves you with gathering treefall.
Even if you're still in the warm African savanna do you realise how much gathering you'd have to do, not just for cooking if you were into that yet, but for keeping predators at bay during all those hours of darkness?
Go build a stack of tree fall about a metre high and burn it. That's about the minimum amount of fire you'd need all night to keep you a bit safe.
That's a lot of gathering for your women, 'cause they'd have to do it as you'd be busy with hunting, tool mending and making and doing your rituals to keep peace with the gods
It's a worry.
However, on the other hand, I think we can stop blaming the Romans for the Sahara Desert. It was all those freaking stone age firebugs.