Mother's favourite new appliance. 
(Lasts at least 2 hours on 1 bar, before recharge)
Letouch Rechargeable Hand Warmer 5200mAh Power Bank, Electric Hand Warmers Double-sided Heating Portable USB Mobile External Battery Charger Best Gift in Winter for Women, Man (Silver): Amazon.co.uk: Sports & Outdoors
(Lasts at least 2 hours on 1 bar, before recharge)
Letouch Rechargeable Hand Warmer 5200mAh Power Bank, Electric Hand Warmers Double-sided Heating Portable USB Mobile External Battery Charger Best Gift in Winter for Women, Man (Silver): Amazon.co.uk: Sports & Outdoors