Hi takesh1k0vacs,
I’m glad you were able to find a way to get a Best Mattress Ever shipped to Hong Kong!
Regarding temperature, I don’t know if you’ve seen this article, but there is more about the many variables that can affect the sleeping temperature of a mattress or sleeping system in post #2 here that can help you choose the types of materials and components that are most likely to keep you in a comfortable temperature range.
In very general terms … the materials, layers, and components of a sleeping system that are closer to your skin will have a bigger effect on airflow, moisture transport, and temperature regulation than materials, layers, and components that are further away from your skin and softer mattresses or foam toppers will tend to be more “insulating” and for some people can sleep warmer than firmer versions of the same material.
All foams insulate to a degree, and adding a memory foam topper, regardless of the additives, will tend to “insulate” you a bit more and can actually allow for less exposure for heat exchange (see this article), so this wouldn’t be my first choice as a method of creating a “cooler” sleeping environment. I would look at some of the other things discussed in the link I provided earlier in this post first.
Phoenix