I have never dealt with an RI myself so i wont be much for advice, but i have heard it both ways. Bump the temps up and drop the humidity and vice versa. But me personally until i got the snake to the vet i would bump the temps/humidity up. Or leave humidity where its at... Now dont forget if its a whistling sound "sometimes" its just the snake is coming off a shed cycle and there may be loose skinin the nasal.... But whatever the case i think its a great idea to take him/her to the vet. Good luck