Shiver Strip for Kids

It seems like no matter how warm it is when we go swimming my skinny little kids start to shiver uncontrollably at some point during the outing.  You would think they would then want to get out of the pool but for some reason they still want to play in the water.  What I need is a shiver strip.  This would be a temperature strip that would change color based off the core body temperature of you child.  The shiver strip would be a sticker to stick to your kid on their chest or back.  If a kid's body temperature ever dropped below a certain point the shiver strip would turn bright red.