Under the impression that tomatillos did better in the heat than tomatos, I
planted some a month or so back in my outdoor/open air hydroponic system.
They look great, and are blooming like crazy, but no fruit is setting.

Is it too hot for tomatillos to set fruit right now?

I cut back all my regular tomatos - Russian, Carbon, Wild Cherry, Green
Zebra, Brandywine, so they could send up new growth for the fall season.
They're doing well (in the same system) but don't look nearly as happy as
the tomatillos.