There are a great many dangers that are associated with the use of heroin, and all of them are quite terrifying. None of those dangers compare to the danger of a "hot dose" though, which is dangerous and horrifying.
What is a Hot Dose?
A "hot dose" is the name given to a dose of heroin that has been purposefully tainted. Most often times, the dose is spiked with battery acid, it is done on purpose, and usually with a malicious intent.
What Happens if you Shoot a Hot Dose?
You die. It is as simple as that. This is a dose of heroin that is designed to kill the user as soon as the heroin/battery acid reaches the heart.
Who Creates Hot Doses?
Hot doses can be created by anyone who has heroin and wants to make it deadly by adding the battery acid. As horrifying as it may sound, the majority of hot doses are mixed by one junkie and given to another, in order to kill and rob that person and blame it on an accidental overdose. The hot doses also have been reported to be used to shoot-up someone that was passed-out to simply just kill them and make it look like an overdose.
And then there are the truly frightening cases of drug dealers who for whatever reason give out these doses to customers who angered them, were always late with payments, etc. There have also been cases of people who are just crazy and started selling hot doses simply to kill others.
Hot Doses are simply killer doses of heroin. You cannot tell the difference between a regular dose and a hot dose, so the danger is always there that this use of the drug will be a fatal one. This is why heroin itself is a terrifying drug, with many more dangers that just the risk of addiction and accidental overdose.