Sauna experiment - Celsius to Fahrenheit converter This is my program for a sauna. It is a Swedish sauna meant to only understand Celsius, but the user can only understand Fahrenheit, so when the user inputs Fahrenheit, it is converted to Celcius. Afterwards, the Celsius is rounded to an even value when presented to the user, to get rid of all the decimals from the conversion.

class Program
{
    static void tempCheck(double temperature)
    {
        if (temperature &lt; 0)
        {
            Console.WriteLine("The sauna has now become a freezer, \nCelcius: {0}", Math.Round(temperature));
            Console.WriteLine();
        }
        else if (temperature &lt; 73)
        {
            Console.WriteLine("This temperature is too low for sauna use, \nCelcius: {0}", Math.Round(temperature));
            Console.WriteLine();
        }
        else if (temperature &gt; 100)
        {
            Console.WriteLine("You will be boiled alive if you use the sauna, \nCelcius: {0}", Math.Round(temperature));
            Console.WriteLine();
        }
        else if (temperature &gt; 77)
        {
            Console.WriteLine("This heat will scald you, please lower the temperarture, \nCelcius: {0}", Math.Round(temperature));
            Console.WriteLine();
        }
        else if (temperature == 75)
        {
            Console.WriteLine("Perfect heat for sauna!");
            Console.WriteLine();
        }
        else  
            Console.WriteLine("This temperature is adequate for sauna use! \nCelcius: {0}", Math.Round(temperature));

    }

    public static double FahrToCels(int fahr)
    {
        double fahrenheit = (5.0 / 9.0) * (fahr - 32); 
        return fahrenheit;
    }

    static void Main(string[] args)
    {

        double temperature = 0;
        Console.WriteLine("Enter a desired temperature between 73 och 77 celcius");



        do
        {
            try
            {
                int fahrenheit = int.Parse(Console.ReadLine()); 
                Console.WriteLine(temperature);
                double celcius = FahrToCels(fahrenheit); 
                Console.WriteLine(celcius);
                temperature = temperature + celcius;
                tempCheck(temperature);

            }
            catch (FormatException)
            { 
                Console.WriteLine("Please only enter whole numbers, no decimals");
            }
            catch
            {
                Console.WriteLine("Error");
            }

        } while (temperature &lt; 73 || temperature &gt; 77);
    }
}
}
Review

Several issues have also been addressed in the comments below your question. A quick re-iteration:


You state the user only knows Fahrenheit, yet you ask them to input in Celcius: Enter a desired temperature between 73 och 77 celcius.
For each bad attempt, you add the new input to the previous input temperature = temperature + celcius;. This doesn't make any sense at all.
You should be able to read from code what the code is about. tempCheck(double temperature) doesn't tell us the unit of the input. Prefer celcius or a custom class Celcius.




tempCheck(double temperature)

This method has two very different responsibilities: (1) detect status by provided temperature (2) render status information to user. These should be two different methods to allow for reusability of the status check.

The status could be an enum:

enum TemperatureStatus
{
    Normal,   // 73°C - 77°C (but not 75°C)
    Perfect,  // 75°C
    Freezing, // &lt; 0°C

    // and so on ..
}


Have tempCheck return the status:

static TemperatureStatus tempCheck(double celcius)
{
    if (celcius &lt; 0) return TemperatureStatus.Freezing;

    // and so on ..

    return TemperatureStatus.Normal;
}


Rendering the status message can then go to its own method:

static string RenderStatus(TemperatureStatus status, double celcius)
{
    celcius = Math.Round(celcius);
    switch (status)
    {
        case TemperatureStatus.Freezing:
            return "The sauna has now become a freezer, \nCelcius: {celcius}";
        // and so on ..  
    }
}