In case of an emergency, the legislative body may pass a resolution by a four-fifths vote of its members declaring that the public interest and necessity demand the immediate expenditure of public money to safeguard life, health, or property. Upon adoption of the resolution, it may expend any sum required in the emergency without complying with this chapter. If notice for bids to let contracts will not be given, the legislative body shall comply with Chapter 2.5 (commencing with Section 22050).