Thermoregulation through sweat gave early hominids a clear advantage when hunting. In contrast to many of its prey animals, Homo erectus already possessed many times more sweat glands and was able to hunt for endurance. Even today, humans cannot walk in the heat without sweat. The evaporation of sweat cools our bodies. Sweat, hidrós in Greek, consists of 99 per cent water. Walking in the summer heat, which according to projections will increase due to the deteriorating climate, is therefore not possible without sweat.

As part of the international Art del Caminar Encounter in Girona/Banyoles (E) which took place from 1 to 6 July 2024, I realised my project ‘Sweat Mapping’. On the third day of the conference, the group of international artists undertook a 5-hour hike, starting in the afternoon but still in the summer heat, from Girona to Banyoles. On the walk I did talk to participants about walking in the heat and ask them for drops of sweat/sweat liquid to make a sweat mapping. The drops were applied to a piece of glass, following a line of the natural water system between Girona and Banyoles, which was shown on a sketch under the glass. In the end, the sketch with the water system was removed and only a very fine drawing of almost invisible sweat residue remained on the glass. The next evening, the project was concluded with a short performance on the shore of Lake Banyoles, in which the drawings on the glass shimmered in the evening light. A short audio piece was created afterwards from the sweat conversations held during the hike.