if it was properly cooked yesterday and then cooled soon after you finished eating, been in your fridge overnight and then heated thoroughly today, you’d be bloody unlikely to be at any risk
The notorious problem with rice is a bacterial toxin which is produced by bacteria that (as spores) survive the initial cooking (esp if the water’s not fully at boiling point) and then start to grow on the rice if it’s left warm for a length of time. While growing they produce toxins that are in/on the rice.
That bit has to have happened in order for any of the following to be relevant:
To destroy the fast-acting vomity toxin you’d have to get your reheated luch REALLY hot, not just reheated to eating temp, and so that’s why it’s fairly common to get this effect.
The (more scary in healthy people) bottom-based splats toxin is destroyed if the food gets above about 60% for a few minutes, so even moderate reheating would protect you from that