Hello CraftyRascal, that is the usual protective measure Haworthias do when the conditions are too hot and dry. It goes somewhat dormant, so it is not doing much at all. It closes down its rosette, and waits it out when cooler conditions returns. I have learned now to position them in the shadiest side of my garden, still with bright light, but in shade, since they cannot take our intense sun and heat.
When that happens to my Haworthias, I just let it do so, I still water, at least once a week, just enough to keep the soil damp, so the roots does not go dried out. It will just stay dormant. Just got to be patient. It is drought tolerant, but not that heat tolerant. If forecasts even calls for triple digits, then I may go twice a week watering, to help the roots cope from excessive dry heat here.
Your plant looks okay, as long as there is no undue off colored leaves, or rotting at the center, then it is okay. If you do see dried out outer leaves, just remove them, those will be older leaves.
I do not know where you are located, over here, we are feeling Fall temperature cool downs, so my Haworthias are waking up from their summer time slumber.
