Q: What temperature should your Macbook Pro go up to when watching YouTube videos?

Hi I was just wondering what temperature your MacBook Pro should go up to when watching YouTube videos. Is it ok for it to be going up to 90 degrees C after around 30 minutes when watching YouTube videos? If not, what temperature is it ok to go up to when watching YouTube? My MacBook Pro is iOS 10.10.5 I have tried not watching YouTube videos before and the temperature goes up to 50 degrees at the most but it only gets extremely hot when I'm watching videos which is supposedly the problem but I am not exactly sure. Thanks.