The term heat is used colloquially for heat when doing unusually high temperatures. Technically and physically, only the term heat or thermal energy is used and the corresponding temperature specified.
From heat, however, one speaks, for example, at a high air temperature, especially in the tropics and deserts, in the summer months even in subtropical and temperate latitudes. The term is here used broadly as an expression of unusually high air temperatures, but was also previously defined by a daily maximum temperature of about 30 ° C, one then spoke of a Hitzetag. This term is deprecated and would be replaced by the concept of summer day or even through the hot day. An unusually long period of directly consecutive hot days, also referred to as heat wave. This can, as in the case of the 2003 heat wave cause great damage and in extreme cases, a " summer of the century " condition.
The perceived ultimately as such heat, however, is rather an expression of the perceived temperature, which measured the air temperature and also, among other things on the wind speed (wind chill ) and humidity ( heat index ) depends. The wind chill temperature is zero wind and / or damp air, significantly higher than for dry, moving air.
In addition, each person designated by virtue of his subjective temperature sensation a different temperature than heat, cold or comfortable temperature, with temperatures above 26 ° C in many cases are perceived as " too hot " and typical optimal values in the range of 20 ° to 22 ° C and 50 to 60 % relative humidity are. If too much heat stress is a risk of heat damage.
Helpful measures in extreme heat are the avoidance of physical exertion during the lunch hours, plenty to drink (water, mineral water, tea), a foot bath with cold water and wearing breezy clothes and if possible the elimination of stockings.