Chedi Chiang Mai

Most of the guesthouses in CM have rooms with a/c, although the cleanliness varies. Just make sure you see the room first. Virtually any guesthouse or travel agent in the city can arrange a whole slew of activities, including jungle treks. The trek I did had a waterfall that we swam in as well as a white water rafting option. Keep in mind though that most of these treks are multi-day and the accommodation will be very basic, with no a/c. Just make sure you have a sufficient amount of water and you'll be fine. Additionally, I would suggest renting a motorbike and driving up to Pai. It's an incredibly friendly town and a beautiful 4 hour drive through the jungle. Damn, I wish I was there right now!!