Sir – In the recent freezing temperatures it is shameful that so many high-street shops along Cornmarket are keeping their doors propped wide open, with no thought for their carbon footprint, or even their own heating bills. What wasteful, ungreen behaviour!

Why do Clarks, Next, WH Smith etc do it? Do they think they will lose customers if they are put to the trouble of pushing a door open? They will certainly lose this one.

I will do my Christmas shopping at shops which use the world’s precious energy resources wisely, and I urge other readers of The Oxford Times to do the same.

Linda Covill, Summertown