No, heads up is used to give someone information you think would be helpful to them. The assumption is usually that they don’t know this information, so it’s not a reminder.
Here are some examples.
I just wanted to give you a heads up that your boss is upset about how the meeting went.
Here’s a heads up: if you want to swim safely in the open water you should have a partner.
The second one is closer to a reminder, but is still told with the idea that the person might not already know that.