Need advice about battery concern

[GRIMM18]

Hi im new here and just have a question about battery safety and heat issues ..I recently started with mech mods I have did a lot of research and I am safe I check for shorts with a multimeter often I USE SONY 30 AMP batteries on 28g dual coil .7ohms built on a clt rda by infinite on a nemy clone by infinite ..so my question is can batteries get warm at all not hot but warm ill feel my battery before use and it feels quite cool then after 5 or 6 hits it warms up very little is this normal oh my mod also gets warm also but I think that is from the atty ..so basiclly what I am saying is are batteries aloud to get warm at all or is this a cause for concern I do tend to worry more then others lol..thanks