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.
1 The symptoms may sound similar, but they feel different from âtrueâ hot flashes. 2  Thyroid cancer. 3  Thyroid cancer can also cause an excess of thyroid hormones, leading to sweating and excessive warmth, but hyperthyroidism is a much more likely cause. 4  Rush of adrenaline.