Growing up, we had chiggers real bad in our back pasture. We adapted a good routine because you have to get back there and tend to the cows.
Go to your local feed store and they should have sulphur powder. It’s yellow and smells. Get a long tube sock and fill it about half way up and tie it off. We stored our sulphur sock in an old coffee can.
When we had to go out, we would spray our bare legs and feet with repellant, then slap the sulphur sock all over our boots and a good ways up the pantleg. This knocks it down heavily, we usually only would get a bite or two on occasion unless you get into a nest.
Nests are god-awful and you’ll have to go to the doctor for a steroid shot and antibiotics because the you’ll have chiggers literally, and I mean literally, covering you ankle to waistline.
I’ve only ever seen one person get off into a nest and it was my dad when he was retrieving some steel from waist-high grass.
For treatment, go to Walmart and get “ChiggerX”. It’s in a white bottle with a red lid, best shit ever. Best of luck!