I taught my son to read at that age. It seemed like an extension of his learning the names for everything so easily. So I taught him the letter sounds by making a PowerPoint presentation with one really big letter per slide. He would sit on my lap and we would "do letters" as he called it. Once he knew the single letters, I made slides where the letters would appear one at a time to form words. He was able to sound out CVC words before he was 3 and he read Bob Books soon after. I eventually extended this approach to vowel digraphs and so forth.
I wouldn't call what we did hot housing. It's not hot housing if it grows that way naturally.
