What temperature kills orchids?

Sustained temperatures below 50 degrees Fahrenheit will be bad for most orchids, as will temperatures above 85 degrees Fahrenheit. However, there are a few species that can tolerate much more extreme conditions, so it’s important to do your research before you buy an orchid to make sure you’re providing the right environment for it. As a rule of thumb, anything below freezing for extended periods will kill a tropical plant like an orchid.