It becomes unbearable not because of heat capacity but because of inability of the body to expel heat. When outside temperature is equal or higher than body te

It becomes unbearable not because of heat capacity but because of inability of the body to expel heat. When outside temperature is equal or higher than body temperature the only way to expel heat is through sweating. For this the air must by dry enough (wet bulb temperature less than body temperature). https://en.wikipedia.org/wiki/Wet-bulb_temperature https://en.wikipedia.org/wiki/Wet-bulb_temperature If body can't expel enough heat it results in eventual death.