the only thing i found that works is taking containers in the house and chucking a cheap double duvet over them (my wife thinks its great having 8 containers in the kitchen) water gets up to about 4 degrees then when i put containers in my motor , i use duvet to cover containers and trolley i also use IPA when temps drop below freezing , At the moment its 5 degrees outside thinking of getting my shorts and a t_shirt on for work today