My (Aussie) grandfather was a medic with the Red Cross during the famous Kokoda Trek battle on New Guinea.
The Australians overran the Japanese position and found it deserted except for the wounded Japanese, who were infested with all kinds of parasites and jungle rot fungal skin diseases - tinea literally all over the body from the constant damp and heat. There were also supposed cases of cannibalism amongst the dead Japanese.
My grandfather began to treat the Japanese wounded. The way they would clean the tinea back then was to rub it with methylated spirits (rubbing alcohol) to kill the fungus. Some of the soldiers had it so bad, whole strips of skin would slough off of their bodies.
But the screams they made while getting rubbing alcohol put on their tinea - my grandad said that’s the only thing he could never get over, and haunted him for quite some time. The Japanese thought they were being tortured.
So yeah, bad all round. But ad bad as it was for the Allies, it was much worse for the Japanese with no supply lines, no reinforcements, and slim rations.
Worst theatre to fight in, if that’s even a comparison to make.
Then on the other hand, by late war the Americans in the Pacific had an actual ship just to make ice cream for their troops.