Eli5: Temperature?

Question

I feel stupid to ask but here goes.

So you can sit in a sauna where the thermometer measures the air at 80oc, and it’s fairly comfortable. But if you sit in water which a thermometer measures at 80oc, you die pretty instantly.

So I get that water is denser and so transmits heat faster – but then… what is the thermometer measuring if not heat transfer???

Tia

In: Physics

Answer 1

The difference between temperature and heat transfer is the reason we have weather indicators like windchill and heat index. Windchill and heat index are the metrics of what the heat transfer is like outside.

For example, if it’s 30 deg F outside and there’s a 10 mph wind, you’ll get colder much faster than if it is 30 deg F and no wind, because the wind blows away the hot air around your body and replaces it with colder air. The rate at which your body cools at 30 deg F with 10 mph wind is the same as if it were 21 deg F and no wind (meaning those two conditions have the same heat transfer). So we define a metric called “wind chill” to say that 30 deg F with 10mph wind “feels like” 21 deg F (and no wind) because those two conditions have the same heat transfer and therefore the same perceived feeling of “cold” to our body.