Alarm on iPhone 11 at midnight

For the past 3 nights an alarm like sound has gone on my iPhone at exactly midnight. I have checked the clock app and turned the sound off on all apps. In addition I made sure all apps were closed before plugging in to charge. Any ideas of other steps to take. My phone felt hot to touch the 1st day this happened and it cooled off when I took it out of purse. In addition the battery drained quickly when it felt hot.