Concrete can be poured and worked with in cold weather, but there are certain precautions that should be taken to ensure that the concrete cures properly and achieves its desired strength and durability. Here are a few things to avoid when using concrete in cold weather:

1. Avoid freezing temperatures: Concrete should not be placed or worked with when the temperature is below freezing (32°F or 0°C). When concrete is placed in freezing temperatures, the water in the mix can freeze before the concrete has a chance to cure, which can cause the concrete to crack and weaken.
2. Avoid rapid temperature changes: Concrete should also be protected from rapid temperature changes, as this can cause the concrete to crack. For example, pouring concrete on a cold surface and then covering it with a heat source can cause the concrete to cure too quickly, leading to cracks and weakness.
3. Avoid using cold water: It is important to use warm water when mixing concrete in cold weather, as cold water can cause the concrete to set too slowly. This can lead to a lower-quality finished product, with reduced strength and durability.
4. Avoid using too much water: In cold weather, it is important to use the minimum amount of water necessary to achieve the desired consistency in the concrete mix. Using too much water can cause the concrete to cure too slowly and reduce its strength and durability.
5. Avoid overworking the concrete: When working with concrete in cold weather, it is important to avoid overworking the concrete, as this can cause the concrete to lose heat and set too slowly. This can lead to a lower-quality finished product, with reduced strength and durability.

By following these precautions, it is possible to use concrete successfully in cold weather, ensuring that the concrete cures properly and achieves its desired strength and durability.