Domain 0≤x≤12 this means the domain (x values) are between x=0 and x=12 and you started measuring the degree of temperature starting at a time of 0 and stopped measuring the temperature at a time of 12 hours
Range -4≤y≤4 this means the range (y values) are between y=-4 and y=4. The range is referring to the degree in celcius based on what time you measured it
Hope this helps!