ḥamam

• reaches beyond fire to the heat of the sun and to warmth the body generates on its own, whether from lying close to another person or from an animal's fleeceExo 16:21Ecc 4:11Job 31:20
• turns figurative for the inner heat of strong feeling, the heart burning with anger or griefDeu 19:6Psa 39:3
• stretches to the burning heat of lust and of drunken feasting, a body inflamed rather than merely comfortableIsa 57:5Jer 51:39

• both name a person warming the body at a fire on a cold day, the plain physical actJhn 18:18Isa 44:16
• both cover the bare bodily need for warmth, whether met or left wantingJas 2:16Hag 1:6

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• חמם is the gentle warmth that keeps a body alive: an old man who cannot get warm, two sleepers who keep warm together, a fleece that warms the poor.1Ki 1:1Ecc 4:11Job 31:20
• It names ordinary natural heat, from the sun that grows hot on the ground to the warmth a bird gives the eggs it leaves in the dust.Exo 16:21Job 39:14

• Both use heat as a picture of strong feeling burning inside a person: anger, desire, or grief that flares up within.Deu 19:61Co 7:9

• πυρόω is intense, consuming fire rather than mild warmth: at the last day the heavens are set ablaze and the elements melt in the heat.2Pe 3:12Eph 6:16
• It is the fire that refines and tests metal: gold purified in the furnace and bronze glowing white-hot.Rev 3:18Rev 1:15

• It covers plain bodily warmth, the kind people need for comfort and survival: an aged king who cannot get warm under his blankets, two travellers keeping each other warm, a poor man warmed by the fleece of the sheep, and wages that never buy clothing warm enough.1Ki 1:1Ecc 4:11Job 31:20Hag 1:6
• It is also used of heat in the world outside people: the sun climbing until the manna melts, a man warming himself at the wood he has just cut, coals too few to warm anyone, and bronze heated until it glows.Exo 16:21Isa 44:16Isa 47:14Ezk 24:11
• Warmth can be what brings life back or keeps it going, as when a prophet lies on a dead boy until the body grows warm, or the ground broods over the eggs an ostrich has abandoned.2Ki 4:34Job 39:14
• When the Hebrew word does turn inward, the heat is usually dangerous rather than admirable: the rage of a man chasing down a killer, a people burning with lust at their shrines, and leaders as hot as an oven with their plotting.Deu 19:6Isa 57:5Hos 7:7

• Both take heat rising inside a person as the picture of feeling that has grown strong: a heart that turns hot while its owner broods in silence, and a spirit kept at the boil in the Lord's service.Psa 39:3Rom 12:11

• The Greek word pictures a liquid brought to the boil, so it names heat at its peak rather than the comfortable warmth the Hebrew word usually describes.Act 18:25Rom 12:11
• In the New Testament it is never said of a body, a fire, or the weather; both times it describes what is going on inside a person who is serving God.Act 18:25Rom 12:11
• The heat is a good thing, praised in one man and commanded of every believer, so it works as a standard for Christian energy rather than a warning.Rom 12:11Act 18:25