Guest Refussal to use Fireplace

[Kyler J Sloan]

Suppose there is an issue with your heater.  

Is it unreasonable to request that a guest use my fireplace (wood is provided) until the issue is resolved?

For some reason, they are adamantly opposed to using a fireplace.  

I am at work at a solution, but what concessions are owed in your opinion if there is a backup heating solution that the guest refuses to use? 

Thanks for any feedback.