The heated room was Dr George Fordyce's. Charles Blagden took the notes and published them in the Royal Society's Philosophical Transactions. On 23 January they went in "without taking off any of our cloaths". The heat warped the ivory frames of their thermometers until every one broke. Mr Banks stayed seven minutes at 211 °F (99 °C). Blagden touched his own side: "it felt cold like a corpse", yet under his tongue he was barely warmer than usual.

On 3 April the fire was kept up all night and the thermometer stood above 260 °F (127 °C). Blagden went in with gloves and a cloth over his face and stayed eight minutes. Next to the thermometer they put eggs and a beef-steak. In about twenty minutes the eggs were "roasted quite hard". In forty-seven the steak was "not only dressed, but almost dry". The gentlemen were fine.

Blagden concluded that "the body has a power of destroying heat". Sweat, he thought, was only an assistant. Today we know it does most of the work. After every experiment they went straight out into the cold air.

Finns repeat this experiment every week. Without the coats.

Dry air, short visits, 1775. Please don't try this.

Would you have gone in?

Sources: Charles Blagden, "Experiments and Observations in an heated Room" and "Further Experiments and Observations in an heated Room", Philosophical Transactions of the Royal Society, vol. 65 (1775).
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