How would you treat this rust?

I know most of you might not even mess with it. I bought the truck out of Maryland it’s now in TN where rust isn’t an issue. I’m not sure how this rust stuff works. I’m not sure if it will stay the same as it is for the rest of my life or if it will progressively get worse.

the reason for my question is mainly because it’s not in a straight forward place like the frame. The spot is under the hood behind the coolant reservoir

and then a spot beside that maybe under the tube that’s for your air intake?

I’ll post pictures before. I can’t just go to spraying something in there it’s tight spot. What would you do?

 

Behind the reservoir id hit it with a coarse wire brush and then paint over. Any other/better pics of that 2nd one?

 

I’ll work on getting better pics. I’m not even sure what that part is. It’s just hard to get access to to clean it and spray it with anything without making a mess.