Answer:
As it was too hot outside, she watched TV inside.
Step-by-step explanation:
Following the rules of formal argument, the most logical and reasonable sentence expresses that the person watched TV inside because it was too hot outside. In that respect, the conjunction as indicates that something occurs the moment that something else is taking place. Thus, the hot weather is happening at the same time that the woman is watching TV, so it is a sensible decision to stay in watching TV during very hot weather.