I think „getting hot“ is also something very subjective.
When you have a situation where the phone really gets „hot“ check out the battery statistics if there is any app causing this.
During charging it’s normal that the phone gets a bis warm especially around 30-70% charging.
Hot means you can fill it through the case and it feels like it would almost be too hot to hold if out of a case.
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No apps using the battery, but it was very warm.