Förstår inte felkoden jag får?? C#

using System;

namespace Bastu
{
    class Program
    {
        public static double FahrToCel(int fahr)//method that takes in int fahr (fahrenheit) but converts it to double cel (celcius) and returns cel
        {
            double cel = Convert.ToDouble(fahr); //converts int to double
            cel = (fahr - 32.0) * 5.0 / 9.0; //converts fahernheit to celsius
            return cel;
        }

        static void Main(string[] args)
        {
            double maxTemp = 77.0; // deklare values so we leter on can use the verible .
            double minTemp = 73.0;
            double optiTemp = 75.0;
            double cel;
            int fahr;

            Console.WriteLine("Welcome to the Sauna!");

            do // the loop starts with asking the user to enter a temerature
            {
                    Console.Write("Please enter a temperature in fahrenheit: ");

                try // The ''try'' will catch a mistake for exemeple is the user write a letter insded of a number
                {
                    fahr = int.Parse(Console.ReadLine()); // the number is read and given the verible fahr
                    cel = FahrToCel(fahr); // the metod FahrTocel is calld to make fahr into cel, witch the program will use from now on
                }
                catch (Exception)// If the use did wirte a letter insede of a number this will happend
                {
                    Console.WriteLine("Please enter only numbers");
                    continue;// So the loop starts from the begining agin and not just stops here
                }

                if (cel > maxTemp)//if the temp is to high the program will as for a new number, as well as telling the use what the temp in now(with only one desimal)
                {
                    Console.WriteLine("The Sauna is too hot! Its " + Math.Round(cel, 1) + " celcius. Turn down the temperature!");
                }
                else if (cel < minTemp)//if the temp is to low the program will as for a new number, as well as telling the use what the temp in now(with only one desimal)
                {
                    Console.WriteLine("The Sauna is too cold! Its only " + Math.Round(cel, 1) + " celcius. Turn up the temperature!");
                }
                else if (cel == optiTemp)//if this is true the loop will end here beacuse the temp is perfect. And the code in this block will aper.
                {
                    Console.WriteLine("The Sauna now has a perfect temperature of " + Math.Round(cel, 1) + "celcius! Have a nice visit!");
                }
               
                else//if non of the above was true this will show beacuse the temp is in den middel of the lowset and highes accepteble, and the loop will end here.
                {
                    Console.WriteLine("The sauna has a decent temperature now of " + Math.Round(cel, 1) + " celcius! Enjoy");
                }
            }
            while (cel >= minTemp || cel <= maxTemp); //deturns how long the loop will continue. 
            Console.ReadKey();
        }
    }
}