You build up tolerance.

Also if it's spicy enough you actually get a drug like effect, a euthoric feeling.

Whole body feels warm and fuzzy while you're sweating buckets.

Imagine MDMA but no love and no energy etc.

Just the sweating and the euthoria and mild fever symptoms.

It happened the first time I tried vindaloo.

It made me high.

The spicy that creeps up and burns more and more over time is usually the type that does it.

But only because the stuff that's immediately hot is difficult to eat enough