Thermophobia: An abnormal and persistent fear of heat, including hot weather and hot objects. Sufferers from thermophobia experience anxiety even though they realize their fear is irrational. To avoid heat, they may live in a cold climate, wear light clothing, stay indoors on warm days, and avoid hot water and hot foods.
"Thermophobia" is derived from the Greek "therme" (heat) and "phobos" (fear). This same Greek word has given us many English words, such as "thermometer" (a device for measuring temperature) and "thermostat" (a device for regulating temperature).
The opposite of thermophobia is cryophobia, fear of the cold.