Does heat applied to a stye help it pop?

Sty: It may actually help and definitely does not hurt. So give it a try with warm compresses overnight

A chalazion (stye): can increase in size before surfacing and then expressing itself. Using warm compresses aggressively with gentle massage to break up solidified material will allow the material to surface and exit thus reducing the size. If in the rare case it does not resolve then your Ophthalmologist can remove it for you.

Stye: how to pop??: Apply warmth and pressure. Don't be afraid to apply firm pressure. This will often allow it to "pop" and, voila, you will get better!