day to night temp change and indoors growing

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The day-night swing is not as important as people say it is for most warmer growing species. Hybrid orchids especially don't seem to care. Unavoidable seasonal swings are much more important, in my opinion. Cloud-forest, and cold to cool-growing orchids, probably consider these day-night temperature swings more important than do warm growers. And any plant will better tolerate hot days if nights are a lot cooler.

As an example, the best I can do in my growing room with an evaporative cooler during our monsoon is about 80 - 90 F / 26.5 - 32C by day and 80 F at night. The orchids are fine with this. I don't even bother with cold, cool nor intermediate orchids, except a couple in a terrarium in the bathroom closest to the home air conditioning unit.

Living in steamy hot Houston, I strongly suggest you save yourself a lot of grief and buy only warm to hot growers, until you feel comfortable growing orchids. We can grow a lot of stuff other people can't!