And sometimes the scalding hot chemicals are also corrosive and/or highly flammable and/or poisonous.
That too.
OP, just to give you an idea of the kind of chems you might be dealing with in organic chemistry:
* sulfuric acid: If you're wearing clothes made from synthetic fibers and you get this splashed onto them, it will lead to a highly exothermic reaction, resulting in melted polymer being burnt into your acid-burned skin.
* concentrated (fuming) nitric acid: the reaction with dry organic substances can be so exothermic that it can set them on fire. Will also form explosive compounds when accidentally mixed with alcohols. Oh, and it's pretty acidic, too. And it turns your fingers yellow.
* ethers: may oxidize over time, forming explosive peroxides.
* dimethyl sulphate: If this gets into your lungs, there will be a delayed reaction where it forms sulfuric acid and burns them. Oh, and it will at the same time alkylate your DNA, giving you cancer.
* sulfuryl chloride: a chlorinating agent that will react with water to form hydrochloric acid and chlorosulfuric acid, which will in turn react with another water molecule to form another molecule of hydrochloric acid as well as sulfuric acid.
* strong reducing agents (ex.: alkali metals, LiAlH4): Will explode upon contact with water.
* organolithium compounds, boranes: Will spontaneously ignite upon exposure to air.
* hydrofluoric acid (HF): as an acid, it is pathetically weak compared to its bigger brothers HCl and HBr. Unfortunately, this makes it even more dangerous, as the tiny molecule can diffuse through your skin and slowly release a toxic dose of fluoride inside your tissues.