I have a similar problem. Can ONLY sleep on my side.....but there are times, when within about five or ten minutes my outer ear gets very hot and very uncomfortable - it prevents me getting to sleep. If I move my pillow to where there is a cold place it is fine,.. for a few minutes. Have tried using those cold things inside the pillow case, but they are too cold for the rest of my head.
TBH, the only thing that really helps me on those night is a sleeping pill. and I hate taking these too often.
GP does give me some mild anti-biotic ear drops, and when I get a bout of this I find if I use that for a few days, then it will clear up.
I wear hearing aids in both ears during the day and am certain it is they that are causing some sort of reaction.
I use a good memory pillow - although when I have one of these bouts, I have tried changing to normal pillows - makes no difference. Like the sound of pillow with a hole in it - where have you seen these?