@Ash2023. He is gorgeous! OK this may be a total stab in the dark, but I have had experience of something similar with a friend's cat. Very similar in appearance to yours. She was off to Australia for almost a month in winter a couple of years back and had a friend moving in Monday to Friday each week and asked if I would visit twice a day Saturday and Sunday which I did. The cat, normally an outdoor cat, would be locked in during that time for the friend's and my convenience, in case he decided not to turn up some nights.
It occurred to me when I got there the first time that the place was really uncomfortably hot (by my standards anyway) but it was winter and I had no way of knowing what temperature she normally kept the place and thought it none of .y business. I noticed a lot of cat hair - two cats, so nothing unusual there.
When she got back, she called me to ask if I had noticed the amount of hair, cat had been to.the vet who could find no reason for hair loss. I pointed out that the temperature in her place had been almost tropical, 24 hours a day, added to which the cat had not been out for an hour or two a day to be able to cool off and that I thought that was why he had decided to moult. Once he got back to his normal routine, his coat went back to normal.