Fetching details from the dictionary...

to burn; to burn down; to go down in flames
to be roasted; to be thoroughly cooked
to be sunburnt; to fade (in the sun)
to glow red (i.e. of the sky at sunset)
to become hot (from the sun)
to be jealous; to be envious
真夏の砂浜では肌が灼ける。
Your skin gets burned on a midsummer beach.
夕焼けで空が赤く灼けている。
The sky is burning red with the sunset.
一日中外にいて腕が灼けた。
My arms got sunburned from being outside all day.