Claw

Its because of the heat wave + due to heat she will dry out more and increase uptake of nutrients from the soil, if the soil is incorrect ph, then she will uptake more of wrong proportions of nutrients. I also suspect of overwatering(make sure when top soil is dry that it is all the way dry to the bottom and not still wet at the bottom because if it is you are never letting the bottom really dry out) and being root bound(or beggining to be) check the size of your plant in relation to the soil, same measurements from the top of the soil into the bottom of the top as it is from the top of the soil into the top of the plant? She looks rootbound.

Neither are doing it any favors but both are easily correctable. Bring your pH down to 6.3-6.5 so you have no nutrient lockouts. A hot day can make her sad but she will recover from it no problem. If the air is really dry, you can spray the leaves right before dark hours (one of the only times I suggest doing this!).