Hi crash68,
Talalay latex is a very breathable foam so many people would be fine in terms of temperature regulation without any “help” but any soft foam that you sink into can be more insulating than a firmer sleeping surface or natural fibers and can affect some people more than others (depending on where you are in the oven/iceberg range).
An outlast mattress pad contains a phase change material that can both absorb and release heat so it regulates temperature in both directions and can even out sleeping temperature “spikes” at least for a while when you are going to sleep until temperatures even out so the benefits may not last over the course of the night. If you read the reviews for an example of an outlast mattress pad here … you will see that it certainly helped many people but there are some people that it didn’t help as much or not at all. Your mattress protector, sheets, and bedding can also play a significant role in temperature regulation. There is more about the different factors that can affect sleeping temperature in post #2 here.
Depending on the thickness of the mattress pad … it may also have an effect on the feel and performance of the soft Talalay topper underneath it and on how well the latex can contour to your body.
Phoenix