Hi Bryce720,
5 lb memory foam is certainly a good quality and durable material so along with the latex there would be no lower quality materials or weak links in the mattress.
While it won’t make a difference because when you are testing a mattress locally your own careful testing and personal experience will tell you much more about whether a mattress is a suitable “match” for you in terns of PPP than knowing the ILD of the latex layers … it’s unlikely (although it’s possible) that the base layer of a mattress would be as soft as 24 ILD.
Latex and memory foam are completely different materials with very different properties and there is more about the general differences between memory foam and latex in post #2 here.
While it’s not possible to quantify the sleeping temperature of a mattress for any particular person with any real accuracy because there are so many variables involved including the type of mattress protector and the sheets and bedding that you use (which in many cases can have just as significant an effect on sleeping temperature as the type of foam in a mattress) and on where you are in the “oven to iceberg” range and because there is no standardized testing for temperature regulation with different combinations of materials … 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.
Some types of memory foam are more breathable than others and/or have less effect on sleeping temperature but memory foam or gel memory foam in general tends to sleep warmer than other types of foam materials (latex foam or polyfoam). There is more about the different properties that can be formulated into memory foam in post #9 here and post #8 here but latex in general is the most breathable and temperature neutral of all the foam materials. While only a minority of people will have temperature regulation issues with memory foam to the degree that they will be uncomfortable … if you tend to sleep hot then the odds are higher that you may be one of them.
Phoenix