POCUS Safety in EM

According to the British Medical Ultrasound Society (BMUS) guidelines, the Thermal Index (TI) displayed on an ultrasound machine during a POCUS examination in the Emergency Department primarily provides the operator with an indication of:

When using spectral pulsed Doppler during an EM POCUS examination (e.g., assessing for DVT or performing focused cardiac views), which of the following is a key safety consideration emphasized by the BMUS guidelines due to this mode?

The ALARA (As Low As Reasonably Achievable) principle is fundamental to safe ultrasound practice. In the context of performing POCUS in a busy Emergency Department, which of the following operator actions best exemplifies the ALARA principle according to the BMUS guidelines?