Why? 25°C is absolutely fine for working inside, at least for me. A little cooler and I need a sweater and long pants. This summer I've mainly worked at home (no AC, Southern Ontario), because I don't want to bring my winter clothes to work. Combine a room cooled to 20°C, the AC breeze, and me sitting at a desk without a scarf and I have a sore throat in under two hours.