Temperature extremes should be avoided, but can be survived readily. The plants can live after temperatures in the 30'sF, as long as no frost forms on the plant. 100F is survivable if there's air movement. Watch the humidity at extreme temperatures. In their native environment nearly all plants are exposed to constant breezes.
Orchids are no exceptions.
Moving air will help them. It will also cut down on disease problems, either in a greenhouse or a living room. Good air movement prevents cold or hot spots, which can make it more difficult for you to grow the plant well. A small fan will quickly pay for itself by giving you better growing conditions. If you have adequate humidity to raise other houseplants, you have enough to raise orchids.