Thank you all for your responses, it's very helpful!
I'll raise the temperatures, and try to keep the humidity higher, too.
UVB lamp is 10% T5 (it's 80cm long tube, covering about 2/3 of his enclosure). For the heat I'm using halogen flood bulb for the daytime basking, and Deep Heat Projector...
Hi! I'm new to owning a tortoise, so maybe I'm overreacting... But is clicking/popping breathing always a (early) sign of RI?
I have a 1 y-o Hermann's tortoise. He's active, eats, drinks and poops normally & has clear eyes/nose/mouth (no discharge etc, which I've read is a clear sign of RI)...