can yeast kill themselves off

[Mot-Tom]

I work 24 hr shifts. I am brewing my second batch of beer a double red sp 1.078 to start massive amount of co2 production. The yeast says its a 60 to 75 degree. Today when t
I got home the airlock was plugged up the bucket swollen like s blister and the fermenter temp was at least 78 by the temp tape. So I pulled the airlock and cleaned reinserted it so it would work. But is the temp to high I pulled the blanket off to cool but is it to late? Help I hate feeling clueless. Tom

 

[PhelanKA7]

You'll be ok. You might get some unwanted esters (fruity smells and clove). IIRC 110F is about where yeast starts dying. Some styles actually call for fermentation in the 90s so 78 shouldn't be an issue. If some unwanted esters were created for the most part the damage is done but cool it down pronto and do an extended lager to drive off some residuals.