I agree with Len. I don't know what company you would use but AFAIK typical UPS and FedEx warehouses and trucks are not heated, and if they are its probably not enough to keep corals at their optimum 77-82 degree range. On the other end of the spectrum, in certain climates and seasons warehouses and trucks can get way too hot. Ive had to work in a UPS warehouse in So Cal in summer and its very hot and stuffy. Ever been in the back of any delivery truck? Its bare plywood with sheet metal sides and tops. No insulation makes for extreme temperatures. But, even if temperature wasn't a problem, as Len said, live animals release too many bad things into the water. First of all, they have waste. Imagine being stuck in a small space for 2 days living in your own filth and waste. Not a pretty picture. Second, most inverts release toxins when they are stressed. Third, any livestock we would buy needs oxygen. Even though most stores ship the bags full of pure O2, there is still a limited supply of oxygen that will eventually run out. So there you have it, at this point I don't see any possible way to successfully ship marine livestock over two days. Sure, a small percentage will survive, but what you spend on the losses will be more than the difference you pay for overnight shipping, not to mention all the living organisms you can potentially kill. Maybe one day something will come along to revolutionize the way living animals are shipped, but at this point it is still a difficult task. Even overnight shipments are still a risk, though luckily not that big of one anymore. HTH
