Both heat and ice are fine to use for lower back pain. You should use whichever one feels best. 

What is better for lower back pain, ice or heat?

What is best is determined by what feels the best for you. There is no substantial difference between the physiological changes that take place when using heat or ice. 

Based on newer research, ice does not significantly reduce inflammation, and heat does not significantly increase inflammation. If this is the case, then the best solution is to choose whichever one makes your symptoms feel better. 

Can heat make back pain worse? What about ice?

It’s unlikely that heat or ice will make back pain worse. The only way that this would happen is if the heat or ice that you add, after applying it for several minutes, starts to cause more discomfort. In all likelihood, you could just remove the ice or heat as soon as you started to notice the discomfort increasing. 

Summary

I’d write more on this topic if there was more to write about. If you have any questions or this didn’t adequately explain what you were looking for, please send me an email to nathan@kadalystpt.com and i’ll make sure to update this article with relevant information.