Does it need to be at a certain temperature to set correctly?

I also learned that in colder tempertures if you use hot water to mix it will set faster

The ideal placement temperature for QUIKRETE® Fast Setting Concrete Mix is 70 degrees Fahrenheit, but it may be placed at temperatures between 50 to 90 degrees Fahrenheit. The set time may increase when placed below 70 degrees Fahrenheit and decrease when placed above 70 degrees Fahrenheit. Below 50 degrees (but above 32 degrees Fahrenheit), cold weather precautions must be taken to promote proper curing. These include, but not limited to, the following: store the bagged concrete in a warm temperature before use, use warm (not hot) water to mix, and ensure that the concrete is protected from freezing for at least 48 hours using plastic sheeting, insulated blankets, or other means. If these preventive measures cannot be taken, it would be best to wait for warmer weather.

Yes. Colder it is the longer it will take to set. Warmer the opposite. Idea temperature range for normal set time is typically between 65 and 80 degrees Fahrenheit.