Bye Shi. Okay, tell me when you ready the cups... Hot water should be as hot as you can withstand without immediately taking your hand out, normal should be as normal and close to your bodies temperature as you can, and cold as cold as you can get.
Okay, then get one bowl in place of the 3rd cup. Fill cups with hot and cold water and bowl with normal. Cause you will need to put only one hand in cups and both in bowl...
1. First you make sure that normal water feels neither cold nor hot by putting both of your hands in the bowl with normal water. Hold them there like that until water feels the same for both hands.
2. After that, put right hand in cup with hot water and left hand in cup with cold water. (reverse order is ok too). Hold them there like that until cold water stops feeling cold, and hot water stops feeling hot.
3. Put your hands back to bowl with normal water. What does it feel like for each of the hands?