Back in the early 2000's (maybe 2004-2005) I remember buying a can of Coffee from WHSmiths which was self-heating - I think through some exothermic chemical rea

Back in the early 2000's (maybe 2004-2005) I remember buying a can of Coffee from WHSmiths which was self-heating - I think through some exothermic chemical reaction. It was also really bad as I recall, more like an instant Nescafé than something you'd get in a coffee shop. I didn't repeat the experience.