WHOLE CHARACTER
热rè
hot; heat (temperature); feverish; having a fever; enthusiastic; warm (热心, 热情); popular; in demand (热门)
热 is hot — hot weather, a fever, warm enthusiasm, and anything trending hot.
ZDIC's header names 执 as the sound side, while graph history gives the traditional 熱 its exact sound piece as 埶 (yè), which simplified into the modern 执 shape. The fire bottom carries the meaning; modern and historical pieces are kept separate.
MODERN UPPER PIECE (THE SIMPLIFIED SHAPE OF THE HISTORICAL SOUND SIDE 埶)
执zhí
to hold; to grasp
Standalone meaning is kept separate; the exact historical sound side of 熱 was 埶 (yè), which simplified into the modern 执 shape.
In 热: modern upper piece (the simplified shape of the historical sound side 埶) Modern resemblance to rè is noted as such; the exact historical sound piece is 埶.
MEANING: FIRE
灬huǒ
fire (from 火)
The four-dot bottom fire form; not a standalone page.
In 热: meaning: fire The four-dot bottom fire form of 火.