The school where I went from 7th to 11th grade was the same way. The radiators had those exact two settings, and no one wanted to sit anywhere near them, in case Old Faithful went off! No AC either, and teachers would bring their own fans from home to make things tolerable in May and August. We usually got out the last week of May, and went back during the last week of August.

It used to be if you wanted to be hotter than hell go to Canada in the winter and if you wanted to be colder than hell go to Arizona in the summer. HVAC has gotten much better.