Well, they aren't happy for one thing!
No doubt its too hot for them. That kind of damage looks like hot and dry damage, AKA low humidity, hot temps. Definetly start ventilating and maybe spray some distilled water in the air to bump up humidity, or buy an ultrasonic humidifier, and no it isn't a goner, looks ok to me, just a bit....burned.
EDIT: on the other 2 plants, look like N. fusca, uh, they don't look like they will make it...wow those are some serious temps you have in there.