Health topics – What is legionella? managing legionella in hot and cold water systems lower temperatures managing legionella in hot and cold water systems managing legionella in hot and cold water systems http://www.hse.gov.uk/healthservices/legionella.htm http://www.hse.gov.uk/healthservices/legionella.htm Health topics – What is legionella? http://www.hse.gov.uk/healthservices/legionella.htm