Raspberries, I find, come on more suddenly than blackberries, and it pays to pick twice a day.
I like to have both hands available for this sort of thing, so a nail apron full of repurposed yogurt containers fills the bill.
For awhile there, I was just filling the containers, lidding them, labeling them with a Sharpie, "Rasp 13," and popping them in the freezer. But ran into a space problem, so started dumping loads into the slow cooker. There's a high of 91F or so all this week, so the cooker and the water-bath canner were carried out of doors, where they would not burden the house with extra heat. I smashed the raspberries with a potato masher, then put the cooker on high, with a screen over it to let the steam dissipate, held down (it's a but twisty) with a pair of scissors.
The cooker sat on "low" overnight, and in the morning the preserves were ready for the canner. The hot plate we use for this is slow (110V is not as efficient as 220V, or gas, which we do not have), but it gets the job done. I labeled the jar lids "Rasp 13." In an older post I mused on future labels, and sure enough, here we are.
Meanwhile, in the heat, the garden is doing its own cooking. When not canning, I mostly am moving soaker hoses.