I am really concerned about my cat she seems to be unwell. She is off her food and has been acting out of character today she is lying in corners of the room and under chairs and wont let me come near her when I try she hisses which is not like her at all.
It's very probably the heat, gordie - if you are suffering, so is she. Is she still eating, drinking plenty of water, and still going to the toilet as she should be? All our cats are really lethargic in this weather, and just want to be left alone.
However, if you are really worried about it, ring your vet in the morning to get some advice. Not need to take her in unless they ask you to
Now, in some ways I can understand why you put this in "Body and Soul" but you might get more answers if you also put it in "Animals and Nature". Could well be the heat as has been suggested.
She's probably grouchy due to feeling overheated, let her be and let her find the cool spots around your house..Im sure she will be fine. But if no change in the morning and you are still worried then you must ring your vet.