Not cooled; allowed to warm up or overheat(adjective)
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Use "uncooled" in a sentence
"Mexican houses, ..... unheated in Winter, uncooled in Summer, and uninsulated all the time."
"Yet the regulators at the NRC remain wary of listing the word that everyone else in the world uses to summarize the full horror of what will ensue if uranium fuel at the core of a commercial nuclear power plant is left uncooled long enough for it to melt."
"However, if your system is in good condition, you'd be better off sealing leaks in the system and insulating any ductwork that passes through uncooled spaces."