Heat reactive

Could have used another body part I guess, but thought I'd be traditional and use my hand to test the heat reactive cover on the fascinating book I've just begun reading.

A vital aspect of life. Undervalued by many. Good to have some science to reinforce what many of us already felt to be true (!). Of course much emphasis on touch in early years, will be v interested in whether the book explores touch for elderly.

Apologies for poor photo quality. Phone shot in bed - long day, shattered.