i play minecraft and then it just crashes.

Put the summary of the bug you're having here
After i play minecraft for about 10 mins it crashes.
What I expected to happen was...:
Describe what you thought should happen here
I think it shouldn't crash
What actually happened was...:
Describe what happened here

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ... Play minecraft
3. ... Cry