Hose on thermostat came off

[neilrmp]

I finally changed my thermostat on sunday after driving for about a month with my car not getting up to temp, I taught I put everything back the way it should be, but while test driving it about 50 MPH I got "check coolant level", with smoke coming from my hood, after a quick check I found the upper hose from the thermostat off, I think it's because it was not installed properly but I am not sure, after re-attaching it and filling back up with antifreeze everything is back to normal..