Mount Kenya is 150 km south of the equator in central Africa. As is the case in equatorial mountains, it is also true that that freezing occurs most nights on tropical mountain tops. There are 11 small glaciers on Mount Kenya. The elevation of Mount Kenya is about 17,000 feet.
For many years, I over-wintered parsley using Wall-O-Waters. The device is simple. It is basically a teepee of tubes you filled with water and placed it over the plants you wish to help in overwintering. During the day, the sun melts any ice that formed in the tubes. At night, as temperatures fall, ice forms in the tubes. 80 calories are released with the freezing of each gram of water. The air in the Wall-O-Waters remains at or just above the freezing point. There is a slow steady heat release heat as freezing progresses. Wall-O-Waters are available at most quality garden centers and at a few fly-by-nights as well.
Lobelia telekii produces an inflorescence of flowers, each with a corolla of liquid in each. Like the Wall-O-Waters, as night cools down and freezing begins, so too does the 80 calories keep the flowers of the inflorescence warm. In this case the ice nucleating agent is a bacterial polysaccharide.
The story goes that hikers pop out of their sleeping bags, then out of their tents and whiz over to bushes where they bump into the Lobelia and a tinkle of tiny ice cubes. What a time for a happy hour!
Please remember that the calories (cal) here are 1/1000 the size of a diet calorie (Cal). So there are 1000 small calories in one Diet Calorie. A 100 diet Calorie potato becomes a 100,000 calorie snack for the scientist. They have to watch their figures.