I love coffee. Lots of coffee shops serve coffee hotter than I would like. When I was a kid, I blistered the inside of my mouth with a hot drink. That was 30 years ago, and I still don’t want my drinks above 150 ℉ (65 ℃).

My wife and I were on a road trip, and this conversation happened pretty much exactly. She was kind enough to get me a cup of coffee while I filled the gas tank. The coffee arrived at a superheated temperature. I was afraid a harsh vibration would cause the whole volume to vaporize. We came up with a safety mascot named Steamy the weasel. He reminds people about hot coffee. That’s his job.

For those born in this century: There was once a Lawsuit against McDonald’s about coffee that was too hot. There was even a Seinfeld episode about this phenomenon. There’s also a documentary?

On a related note, more coffee is not necessarily better. I’m not giving up coffee. But I’ve noted that I have to be careful. My tolerance seems to be on the high side. I can drink 8–10 cups and be fine. Rates of caffeine metabolism can vary by 40x. But if I drink more coffee than I metabolize, I build up to levels that cause side effects. These can include anxiety and poor sleep.

Caffeine blocks adenosine receptors. Adenosine makes you feel fatigued. You want coffee to wear off shortly before you are going to bed. Ideally, adenosine would peak just as your circadian rhythm is suggesting sleep. So a big bolus of caffeine right before getting out of bed is ideal, though a little hard to implement.

P.S. Thanks to Connor Macphee who helped make the comic. A version of this post originally appeared on my blog.