Extreme heat poses significant risks to public health, particularly for heat-sensitive individuals and those without access to cooling or hydration. The HeatRisk system identifies groups most vulnerable to heat-related illnesses, with categories ranging from minor to extreme risk. Research shows spikes in emergency room visits and fire department calls during 'Major' and 'Extreme' HeatRisk days, underscoring the severity of these conditions. Even on 'Low' risk days, heat can still threaten sensitive populations, highlighting the need for continuous precautions.