Liquid heater with temperature control

A fluid handling device comprising:

• (a) a channel structure defining a channel extending in a downstream direction;
• (b) an elongated wire extending across the channel in a widthwise direction adjacent a downstream end of the channel;
• and
• (c) an exit structure bounding the channel at a downstream end of the channel, the exit structure defining a slot extending across the channel in the widthwise direction in alignment with the wire, the slot having a cross-sectional area smaller than the cross-sectional area of the channel, the slot being open for flow of fluid exiting from the channel, the exit structure further defining a pair of collection chambers disposed on opposite sides of the slot and offset from the slot in lateral directions transverse to the downstream direction and widthwise direction, and a pair of elongated lips extending in the widthwise direction and separating the chambers from the slot, the collection chambers being open in the upstream direction and extending downstream from the lips, the exit structure further defining exit bores communicating with the collection chambers and open for flow of fluid exiting from the channel, the exit bores collectively having cross-sectional area smaller than the cross-sectional area of the slot.