So called because the summer heat rises with Sirius (aka the Dog Star), the brightest star in the constellation Canis Majoris.
Your prompt is DOG DAYS.
Sweat runs down your spine
Heat caresses peeling flesh
The sun, your killer
The Dog Days are now a moniker for the hottest, most miserable, days of summer.
Let me lie bitten
Sleep sweat-stilled through molten hours
Barkless in the sun
Dogstar, Puppyplanet -
The orbit is awry, they say,
Scoundrel sun adrift, afire.