This is one of the two reasons I do not use wood substrate.

When I did use aspen, I also tended to spot clean... The odors in my snake room went up drastically.

I now use unprinted newspaper. This is similar to the packing paper you can get at u-haul, but I get it in roll ends from the local newspaper. They give the stuff away free.

The unprinted newspaper never gets in the way of feeding.

Sorry, I cannot offer advice on your immediate question, being how to know if the snake is okay or not, but you might consider newspaper in the future.