Consider using class Monitor

A simple resolution:

using System;
using System.Collections;
using System.Text;

namespace EnumFreezingInRun
{
// this gives error "The name Temperature does not exist in the current context"
// - now does not
class Tester
{
class Values
{
public enum Temperatures // note changes here
{
WickedCold = 0,
FreezingPoint = 32,
}
}

public void Run()
{
Console.WriteLine("Freezing is: {0}", (int)Values.Temperatures.FreezingPoint); // here
Console.WriteLine("Wicked cold is: {0}", Values.Temperatures.WickedCold); // and here
}

static void Main()
{
Tester t = new Tester();
t.Run();
}
}
}