A pyrogen is a substance that induces fever. These can be either internal (endogenous) or external (exogenous) to the body. The bacterial substance lipopolysaccharide (LPS), present in the cell wall of some bacteria, is an example of an exogenous pyrogen.
Kenya is a major producer of tea and coffee. Within the country, coffee is mostly drunk instant and it is not as popular as tea or Chai. Most Kenyans brew their tea with milk and lots of sugar, serving it scalding hot and very sweet. Lager is also popular in Kenya, with local brands made using cornstarch and sugar, as well as the more traditional ingredients of water, malt and hops.
Left over ugali can also be eaten with tea the following morning. Ugali is relatively inexpensive and thus easily accessible to the poor, who usually combine it with a meat or vegetable stew (e.g. sukuma wiki in Kenya) to make a filling meal. Ugali is easy to make and the flour can last for a considerable time in average conditions. Maize, from which the flour is obtained, is hardy and will grow reliably in dry seasons. For these reasons, ugali is an important part of the diet of millions of people in Sub-Saharan Africa.