What should I do immediately after the fire to protect my rights under the insurance policy?

What should I do immediately after the fire to protect my rights under the insurance policy?

Usually it is a condition under an insurance policy (a requirement) for the insured to notify the insurer within a certain time or as soon as possible after a loss.  You should therefore check the terms of your insurance policy and submit an insurance claim to the insurer as soon as possible after the fire to protect your interests.  

You should also preserve any relevant documents and records relating to your losses, such as receipts for purchasing replacement items, receipts for medical expenses arising from the fire etc. to support your claim.