If you do not get the litter bed to burn or compost, you will most certainly have the wrong bacteria in the compost. The vast majority of bacteria die when the temperature reaches 50 C, which means that the compost does not ignite spontaneously due to the temperature being too low and thus poor composting. Our bacteria can withstand higher temperatures and can take the compost temperature another 10-15 C. At around 60-65 C, the compost starts to burn "self-igniting" and should reach at least 75 C where all fungi, bacteria and where even our bacteria die. It is at this temperature that the compost is "hygienized". This is what is called a compost "burning". Another reason why a straw bed burns poorly may be that the bed is too dry.