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.
Hot flashes, sometimes referred to as hot flushes are characterized by a sudden and intense feeling of heat on your face and upper body. These hot flashes, that can last from a few seconds to nearly an hour, are often accompanied by sweating, increased heart rate, nausea, headache, anxiety, dizziness, and weakness.