Honestly, i don't make much of them, but then I live in Australia where there'll be several days of 40C temps every year and around half the days between October through april is above 30C.
The only issues I have with plant viability is when they aren't established, if the root system hasn't developed well (like after I've transferred seedlings) and then a few days of very hot days they get fried (but that's not surprising, inability to access water tends to result in death for anything) other than that though no issues. No sudden death, no irreparable damage (some plants wilt a but but bounce back over night).
Not really like cold tolerance (which generally persists for weeks at a time rather than every other day) with death very likely, so that probably plays a part in the lack of info on the topic.
