First you get your son medical attention, have you done that ?
What is the money value of the doctors bills and other costs for the injury ?

What type of neglect was it ( was it something that as the tenant you should have also been doing ?)

What type of heater, was the child doing anything they should not have been that helped cause the injury

Has the problem with the heater been fixed.

Prior to the injury what type of notice did you provide the landlord that it needed to be fixed

Er said 2nd degree burns, get report in 2 weeks he is 1 he was walking in walker to the next room n steped on it.a gas furnace with floor grate landlord stated didn't get hot
Told him in oct.and he never did anything

I didn't pay rent now he is telling us we have to leave by dec 31,when he hasn't fixed anything in the house

If you did not pay rent, so they are evicting you for non payment ?

Also how and when were they notified that the heater was not properly shutting off.

** a open floor heater ( did not even know they still made those) but the older units can get very hot

First, please don't use the comments feature to post followups, Use the Answer options instead.

So if I follow this there is forced air heating in your apartment, but that grate never got hot. Then one day the heat came up and your child stepped on it and got burned? Is that the situation?

So it appears you complained to the LL that you weren't getting heat and he finally fixed it, without telling you.

Whether the grate was working you should have prepared for it working and protected it from your child.

So what is it you want to do? Get the LL to pay your bills or what?

You should not just withhold rent; you give it to a lawyer to hold in escrow while you file formal complaints. If you've withheld rent (how many months?), you may not be able to stop the eviction, apart from any claims regarding injury.
You might find that a floor grate over a furnace is not legal in a rental, so ask the local building inspector. This may not really help you with a place to live, however. Call Social Services.

As noted you cannot just decide to stop paying rent. If you feel the landlord hasn't made required repairs there is a process to follow depending on prevailing laws (ANY question on law needs to include your general locale as laws vary by area).

By the same token, the LL can't just tell you to leave. He has to follow the prevailing law for eviction.

For us to help further you need to tell us where you are, how long you have lived in the unit, whether you have a lease and, if so when it expires, what repairs you have requested that haven't been made, etc.