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.
while the precise cause of hot flashes remains unclear it is largely accepted that the sensation stems from the reduced rate of estrogen production during menopause this reduction causes the body s internal thermostat or the hypothalamus to send certain temperature regulating signals throughout the body