You will find on really cold days your brush head and jets will freeze up
Re Spruce's reply and concrete corrosion, There is a product called Ice Melt from Basic Solutions Ltd Harrogate. that is 6 times more effective than salt, doesnt corrode metal or concrete, biodegradeable, doesnt damage carpets or animals. Available from IKEA http://www.basic-solutions.co.uk/icemelt.html