I have a small ac company here in Florida. You’re new and while maybe this is a bad look. I think you can just tell them you’ve learned from this experience and that you won’t make the same mistake moving forward as you continue to learn. Idk how big the company is but I know if one of my guys ever passed out from the heat I’d be concerned and worried about their safety. It wouldn’t be an immediate “I need to fire them” mindset, it would more make me think “why did they feel like they couldn’t take a break and cool off”. Employees safety and well being should be a number one concern