Okay kiddo, did you know that in January 1977, there was a time when it got really, really cold in some parts of the United States? This is what we call a "cold wave."
Some people lived in places where it was already really cold, but during this cold wave, it got even colder. Imagine being outside and feeling like your toes and fingers might freeze off because it's so cold!
This cold wave lasted for a few weeks, where temperatures were far below what people normally expect in winter. This caused a lot of problems for people and things around them.
For example, sometimes when it gets very cold, pipes can freeze and break. This is what happened to many homes during the cold wave of 1977. People have to fix the pipes before they can use the water again.
The animals also had a hard time during the cold wave. Some animals couldn't find food because the ground was frozen, and it was harder for them to move around in the snow.
People had to be careful when they went outside because there was a danger of getting frostbite. Frostbite is when your skin freezes and turns white. It's very painful!
In some places, the cold wave was so bad that schools and businesses had to close for a few days until it got warmer. Even planes and trains had to be canceled because it was too cold for them to work properly.
So you see, a cold wave like the one in January 1977 can be dangerous and cause a lot of problems, but fortunately, it doesn't happen very often.