It also hit 100 degrees last week (two days), so we took Orion to the pool for the first time. It was lots fun. He has so little body fat (he's 10 percentile in weight), he started shivering. I took him out of the water and he kept on pointing to his friends in the water indicating he wants to go back in. So I took him back in and held him close to my body instead of holding on to the baby donut he was sitting in hoping it would keep him warmer.
That didn't work and he continued to be cold and started shivering more. When he tried to make some sound or say something, he would stutter because his body was shaking. I was so busy laughing but eventually decided I need to take him in and put him under warm running water to warm him up.
Later on husband told me that he was like that when he was young. He didn't have much body fat either and could never stay in the water more then 30-45 minutes or else he gets too cold. Orion's just like a typical kid, isn't he? Rather stay and play and ignoring whatever discomfort he's experiencing.