Methods, systems, and devices for wireless communications are described. A user equipment (UE) may be configured to satisfy an uplink transmission power criterion, such as a specific absorption rate (SAR). The UE may be scheduled to transmit a first uplink message via a first frequency band and a second uplink message via a second frequency band. The UE perform power scaling on the first frequency band and the second frequency band to satisfy the uplink transmission power criterion. For example, the UE may select a first transmission power level for transmitting the first uplink message and a second transmission power level for transmitting the second uplink message based on a function of UE transmission power level over a preceding time interval. The UE may perform uplink power aggregation techniques to temporarily boost transmit power while satisfying the uplink transmission power criterion.