Kind of like calling your doctor and saying "I don't feel well, what can I do?"
What type tortoise?
Where are you located?
Does your tortoise get outdoor time?
Do you already have a UVB source?
How big is your enclosure?
Is it and open table or closed chamber?
What are the normal ambient temps where the tortoise is kept?
Russian Tortoise
Upstate NY
No outdoor time
I have a UVB source
8ftx5ft enclosure
Open Table
70-75 on the cool end 85 on the warm end basking spot gets to 90-92