Hot weather pours - how do you all slow things down?

I pour in the heat most summers becuase around here the cool weeks are booked solid, so my take is you plan the pour around the weather instead of hoping it behaves. Last July I did a shed slab and we started mixing at 6 in the morning, had everything on site the night before, and staggered the loads so no batch sat in the truck longer than it had to. Got it down in sections and never had a panic moment. The trick that made the biggest difference for me was asking the batch plant for cold water in the mix. Slows the set down noticeably without messing with the strength. I also keep a hose nearby and mist the subgrade right before the concrete goes down so it isn't sucking moisture out of the bottom. On evaporation retarders, I've used one on a big garage slab on a windy 90 degree day and it did buy me some working time on the surface. But for a patio sized pour with two people, I'd say a 6am start and a helper or two for the finishing gets you further than any bottle does.

As for your ragged edges, they'll mostly disappear under the curing and nobody walking on it will ever notice. The burlap routine you did was the right call, so I wouldn't beat yourself up over the schedule. A Saturday pour that's done beats a perfect pour that's still on the calendar when the in-laws show up.

For a patio sized pour I'm in the camp of just waiting, honestly. I fought a 20x12 slab one August when a buddy coud only help on a Saturday, and we paid for it. The center was crusting while we were still bull floating the far edge, and I ended up with a surface that looked fine for a year then started dusting and crazing where we overworked it trying to beat the clock. My wife's cousin visits more often than her sister aparently, but I still tell her the calendar wins now.

That said, when I do have to pour in heat, I ask the batch plant for chilled water and I keep the subgrade damp the night before so the ground stops sucking moisture out of the bottom of the slab. A spray evaporation retarder on the surface between operations made a real difference on my last one, way more than I expected. What I stopped doing is slapping extra water on top while finishing, because that's what tore up my first slab.

The burlap move you did was right, keep that habit. But ragged edges just from racing the set tells me the crew was two hands short for that footprint, and no retarder fixes a manpower problem. Two people can do maybe 10 feet of edge work before the surface moves on without you.

Total lurker here, first post, so take this with a grain of salt. I did a small walkway last summer with bagged mix and a mixer instead of a truck, and the heat still wrecked me. Learned the hard way that mixing smaller batches back to back means the first ones are alredy stiffening while you're still stirring batch three. Ended up just doing it in short strips across the walk and finishing each one before moving on. Worked okay-ish but the strip joints show a little. Does anyone here break bigger pours into sections like that on purpose, or is that just asking for cold joints you'll regret later?

I'm with the wait it out crowd here. I did a small pad in the middle of a heat wave a few summers back and even with ice in the cooler for the drinking water the concrete was winning. The one thing that actually helped was hanging a cheap tarp off two ladders as a shade roof over the part I was finishing. Kept the sun off the surface and bought me a few extra minutes on each section. If the schedule ever forces a hot pour again that's the first thing going up before the truck shows.

One thing I'd add from a porch pour I did in August a few years back is the difference between sprinkling water on the surface while finishing and misting it from above. I kept flicking water on with a brush because it was stiffening up, and I swear that's what caused the flaking I had to grind down two years later, since all that extra surface water thins the paste right where you need it densest. A fog mist hanging over the slab, not touching it, is the safer move if you have to buy time. Also worth watching for those little dark cracks that show up when the surface dries faster than the bleed water comes up, because that's the point where you either fog it or stop working it.