Hm. Without knowing the exact symptoms, it’s difficult to say. It is worth it to note that, given chandelure’s typing, it would be rather odd for it to feel the heat, so to speak. Perhaps it’s struggling with the humidity, at which point I’m afraid there’s not much you can do besides provide your chandelure with as dry a place as possible to rest. (Space heaters are especially effective with removing moisture from the air, so those may be a worthwhile investment.)
More likely, your chandelure is struggling to cope with the particularly bright and sunny daytime climate of the region. Many ghost-types like chandelure struggle with the brightness of the archipelago—doubly so for trained ghost-types, as their trainers frequently forget that most ghosts detest sunlight. If this is the case, be sure to allow your chandelure to sleep in a dark room during the day and train it only at night. This may wreak havoc on your own sleep cycle, but it will ensure the mental and physical health of your chandelure.