Board Game Arena

Hello!
I'm having issues trying to understand how much heat the game charges for the boost cycle. The instructions make it sound like I only need to pay 1 heat to boost:

Boost
Regardless of which gear you are in you may pay 1 Heat to boost once per turn. Boosting gives you a symbol as reminded on the player mats. Move your car accordingly,you may still be blocked.

When I use boost, it seems to warn me about a random cost:
"You already have 1 Heat(s) to pay, it will change up to 6 Heat(s).
Your currently have 6 Heat(s) in your engine"

How does it decide how many heats to pay?

Thank you!

Boost always has a cost of 1 heat. (Weather may make it free for an area, though. )

When you boost it adds a card to your speed. If you are rounding a corner during that same turn that speed increase means that you have to pay more heat for that corner. That's what the game is warning you about.

In your example it sounds like you've already exceeded a corner speed by 1.

If you boost then you will have to pay 1 heat to boost, and 1 heat for every extra space you move forward - potentially up to 5 extra heat - bringing it up to 6 heat in total.

I thin Paul is right.
Probably 1 heat you need to pay already for a corner overshoot. Then boost (2nd heat), what could potential be a 1 - 4 speed extra, which will cost a potential 3-6 heat.
System gives you your maximum potential heat you beed to pay.