The present invention is to provide a warming member that can effectively warm the sole of the foot when used in shoes (especially boots with poor air permeability) without increasing the air permeability of the inner bag.The heating element for the foot is equipped with: an air inhalation and release material arranged on the insole of the shoe； and a heating element that is a heat-generating composition that is heated by contact with air is enclosed in a breathable inner bag, and is arranged in use The heating element between the sole of the person’s feet and the air inhalation and release material； and the air inhalation and release material may contain air inside and deform to inhale and/or release air.本發明為提供一種不用提高內袋的透氣性，在放入鞋子(尤其是透氣性不佳的長靴等)中使用時可以有效溫熱腳底之腳下用溫熱件。腳下用溫熱件具備：配置在鞋子內底上之空氣吸入釋出材；及在具有透氣性的內袋封包藉由與空氣接觸而發熱的發熱性組成物之發熱體，而且是配置在使用者的腳底與空氣吸入釋出材之間的發熱體；且空氣吸入釋出材可以在內部含有空氣，且會變形而吸入及/或釋出空氣。
