65 ILCS 5/8-10-5
In the case of an emergency affecting the public health or safety, so declared by the corporate authorities of the municipality at a meeting thereof duly convened, which declaration shall require the affirmative vote of a majority of all the members thereof and shall set forth the nature of the danger to the public health or safety, contracts may be let to the extent necessary to resolve such emergency without public advertisement. The resolution or ordinance in which such declaration is embodied shall fix the date upon which such emergency shall terminate, which date may be extended or abridged by the corporate authorities as in their judgment the circumstances require.
The purchasing agent hereinafter provided for, may purchase or may authorize in writing any agency of such municipal government or of the institutions, boards or commissions thereof, if any, to purchase in the open market without filing requisition or estimate therefor, and without advertisement, any supplies, materials or equipment, for immediate delivery to meet bona fide operating emergencies where the amount thereof is not in excess of $40,000. A full written account of any such emergency together with a requisition for the materials, supplies or equipment required therefor shall be submitted immediately to the purchasing agent and shall be open to public inspection for a period of at least one year subsequent to the date of such emergency purchase. The exercise of the authority herein vested in the purchasing agent in respect to purchases for such bona fide operating emergencies shall not be dependent upon a declaration of emergency by the corporate authorities under the first paragraph of this section.
65 ILCS 5/8-10-5