I remember hearing something about high efficiency chemical heating packs being developed which are able to store heat and then release it at a given signal (like those snapping hand warmers) I'd be curious to know if people have heard about something like that as a potential companion tech for this

If these companies were really concerned then a much better approach would be to steer the development of robotic weapons systems in a way that pushes things that you want them to go.

I can think of 3 things of the top of my head.

Designing the control systems to make it clear that the actions of the robotic unit are the responsibility of the people who deploy it and give it orders (for instance having a required tank for the minimum rank to give specific orders and recording who issues what orders)

Optimise systems to target and destroy military hardware rather than troops. Easier for an autonomous unit to recognise and less chance of severely injuring or killing someone, especially if it targets the wrong thing

Design the units to be cheap and set up to be ultimately expendable. Makes it easier to convince people to hold back in a confusing situation if the thing being potentially threatened can be replaced easily as opposed to being a massive investment with limited numbers