According to IIA guidance, heat maps are tools used in risk assessment that visually represent the severity of risks by plotting them on a matrix based on their likelihood and impact. Heat maps are flexible and can be adjusted to prioritize either likelihood or impact depending on the specific context and the organization's risk appetite and tolerance. This recognition that the priority of impact and likelihood can vary allows for a more nuanced and tailored risk assessment approach.
Reference:
IIA Practice Guide: Assessing the Risk Management Process
IIA Standard 2120: Risk Management