His chronicle of his trip, The naturalist on the River Amazons, became a bestseller when it was published in 1863.
Hot flashes and nausea are most commonly caused by hormonal imbalances in the body, most notably, by sex hormones. For women, a decrease in estrogen is often to blame, whereas in men, testosterone deficiency can create the problem. Sometimes, the symptoms occur for reasons not related to those hormones at all.
There is clear evidence that hot flashes result from hormonal changes in the body. Their connection to other health problems, such as diabetes, is also being studied. Obesity and metabolic syndrome are thought to increase the incidence of hot flashes. Some women barely notice hot flashes or consider them a minor annoyance.