Thai food is treacherous because it sneaks up on you. If you take a bite of a hot Mexican salsa it's WOWEE that was hot! and you can back off.
But your first bite of a spicy Thai dish isn't really that hot you can take it and then the next bite is additive - just a little bit more still not too bad and then ten bites in you realize your horrible mistake and there's no way to back out, you just have to fight your way through to the other side.