Ensure the capacitive load at the output is ≤ 70 pF. This is not a hard limit, however it will ensure optimal performance. This can be accomplished by providing short, appropriately sized traces from the SN74HC04 to the receiving device.
Ensure the resistive load at the output is larger
than (VCC / IO(max)) Ω. This will ensure that the maximum
output current from the Absolute Maximum Ratings is not violated. Most CMOS inputs
have a resistive load measured in megaohms; much larger than the minimum
calculated above.
Thermal issues are rarely a concern for logic gates, however the power consumption and thermal increase can be calculated using the steps provided in the application report, CMOS Power Consumption and Cpd Calculation