Inflammation in lungs

It’s hard to answer because it is unclear where the pain is or what the cause is? You mention lung inflammation but that generally doesn’t hurt - so are you uncomfortable from the treatment you had with your practitioner? - or something else?

Either way, heat is generally the best for most pain related conditions (except nerve pain) as you want to improve circulation and healing not create stagnation (which is generally what ice does). For the most part you have to use your own sense of what is helpful - if it feels like it helps the pain then great. You are certainly not going to drive an infection deeper (except, possibly, a topical one) by using a heating pad.

For the most part I would just give your practitioner 3-7 treatments to get you on a good course and you should be fine. And, obviously, the one to ask these types of questions to is the one who knows your entire medical history and that is your own practitioner.