If it's below 40°F, then use cold weather curing techniques. Options for cold weather concrete curing include blankets, additives and heaters.
Concrete Heat Blankets Fast Curing & Does Not Freeze
A Guide to Working With Concrete in Cold Weather - Academy
Concrete Additives for Cold Weather Winter Construction With Powerblanket
Eng, Free Full-Text
Tips for Pouring Concrete in Winter
Stamping Concrete in Cold Weather - Concrete Decor
Stamping Concrete in Cold Weather - Concrete Decor
Powerblanket MD0304 Heated Concrete Blanket - 3' x 4' Heated Dimensions - 4' x 5' Finished Dimensions: Heaters: : Industrial & Scientific
6'X25' 1 Layer Foam Curing Blanket Grip Rite - White Cap
5 Mistakes to Avoid When Placing Concrete in Cold Weather - Ozinga
Concrete Heat Blankets Fast Curing & Does Not Freeze
Tips For Pumping Concrete in Cold Weather Conditions