Need examples of temperature sensation from 30 through 210 F (at ten-degree intervals)

Factual Questions
1

Hi, could use some help with making a list of what temperatures feel like at 30 F (roughly freezing) through 210 F (roughly boiling,) at ten-degree-F intervals:

30 F: Feels like ice
40 F: ?
50 F: cold day
60 F:
70 F: cool/moderate day
80 F:
90 F: hot day
100 F: very hot summer day
110 F: temperature of warm shower water?
120 F: temperature of hot shower water?
130 F:
140 F: hot enough to scald (if water - but what if it is solid dry surface? is it hot enough to burn?)
150 F:
160 F:
170 F:
180 F:
190 F:
200 F:
210 F: feels like boiling water

Can someone help fill in the blanks?

2

I disagree with your 50 degree characterisation. That’s not a cold day. Brisk, perhaps.

3

Humidity and conduction/convection matter a great deal. A smooth metal surface at the same temperature as a fluffy towel are very different to feel of temperature. A high humidity makes it difficult to cool through sweat evaporation. Still or moving air makes a difference. When I am tired, it feels colder or hotter.

On a very hot day, I got on my motorcycle and expected the movement through the air to cool me a bit, like a fan. I could feel the hot blast of the air. I am not sure what the humidity was. But the effect was unexpected.

Humans have been put in low humidity hot boxes and survived extremely high temperatures.

4

And 30 degrees doesn’t feel like ice. That’s a nice end-of-winter day, heralding the melt. In fact, snow on the roof or on roads tends to start melting if the sun’s out, even if the ambient temp is around 30. Good snowball weather!

5

Well, I meant surfaces and substances. By definition, water freezes at 32 F. I shouldn’t have added air in my examples.
Wish I could edit the post: asking only about liquids and surfaces, not air or gasses.

6

Oh. I worked in a place that had extreme temperature testing rooms.
Minus 50C was stunning. Especially due to being able to walk from room temperature in a t shirt, directly into it. There was fairly brisk air movement in it too. When you inhaled through the nose, it hurt. Frozen snot and nose hairs locked down. You could feel it on your eyeballs. It drilled into you real fast. A few minutes and you had to get out.

The hot room was much easier. Plus 50C. But again, you did not want to breath hard through your nose. It burned. A hot sauna does that too. It was quite dry in there. Both rooms had metal racks, full of metal devices under test. You never touched anything in either room without gloves. With the same light clothing. You would last far longer in the hot room.

The hot room was so easy to create and run. The cold room had massive cooling machinery that was always breaking down. Also had to be defrosted all the time.

7

True, but it’s a phase change, and snow at 32 feels quite different from snow at -30.

Snow at 32 is soft, mushy and wet. Snowball weather. You don’t need gloves to make snowballs, though they certainly help your endurance.

Snow at -30 is hard and cold. I wouldn’t want to handle it without gloves. That way lies frostbite.

8

Well, yeah, 50C is only 25C from room temperature while -50C is 75C difference so of course it would be a more mild adjustment. To have the same shock, you’d have to walk into a 100C room (on the upper end of a dry sauna).

9

Thanks for the replies thus far guys.

Mods, can you please edit my thread OP for me: Asking about surfaces (like, touching hot metal), not ambient temperatures

10

It’s funny how the human body adapts. I grew up in Southern California and always thought anything below 60 F was a cold day. Then I moved to Boston and became grateful for those “warm” winter days when the mercury broke 30. On that rare 40 degree day in February I’d be busting out the short skirts.

Now I dive in water ranging from the low 50s to the high 60s. I wear a wetsuit, of course, but I’m already growing to appreciate those “warmer” waters above 60 that would once have seemed too cold to handle. I’m sure if I moved to the Caribbean, though, I’d quickly come to see anything below 80 as chilly.

11

As you noted, 140 water can scald. If your skin is moist, a smooth metal surface at that temperature can do the same. Liquids or smooth surfaces conduct the heat best. More surface area in direct contact. But a hot surface touched with very dry skin, takes longer to burn. A lot of variables. But in general smooth surface or liquid conducts the heat to you faster. A hot wet towel feels much hotter than a dry hot towel. Same with cold. More surface area contact. Metal also conducts temperature differences better. Fluffy stuff of uniform temperature does not conduct it’s own heat well, through itself to you.

12

Does a metal surface at 50 C burn? That is…122 F.

13

It’s not fun to handle the things constantly. Hundreds of devices would be running in the rooms. Swapping out loads would require gloves. You had to use them in the cold room. Hot room, you could do without. But those same devices are used outdoors. On a hot sunny day, they can be too hot to hold. Tested to 50 C, but subjected to much higher temps in use. We have used them in hot deserts. Gloves required.

14

The devices in the cold room would feel very cold at first touch. If you kept holding them. It started to feel like being burned.

15

A few decades ago, I designed a bunch of equipment for a neurobiologist who was involved in pain research. Even though I was just designing equipment, I did manage to learn a little bit about how the human nervous system works.

One problem with your chart is that the human body is good at detecting changes in temperature, but it absolutely sucks at determining absolute temperature. The classic experiment to prove this is to fill two containers with water, one as hot as you can stand it and one as cold as you can stand it. Stick one hand in each container, and leave them there long enough that they both get acclimated to the temperature. Now take a third container filled with lukewarm water, and stick both hands in it. To one hand, the water will feel cool, and to the other, the water will feel warm, even though it’s the same water.

The human pain thresholds are about 5 to 10 deg C on the low end to about 45 deg C on the high end, depending on exposure time (this is direct contact temperature, not air temperature). On the high end there are actually two pain receivers, TRPV1 and TRPV2. TRPV1 activates around 43 to 45 deg C and is also activated by capsaicin, which is why hot peppers feel “hot”. TRPV2 activates at a slightly higher temperature, around 48 deg C or so. Tissue damage starts to occur once you get around 50 deg C or so, which is where I designed the safety cutoff for all of the test equipment I made.

Since the skin and nerves get damaged above 50 deg C, your body really can’t tell the difference between say 70 deg C and 80 deg C, other than how quickly it burns you. You can’t detect absolute temperatures above 50 deg C. Similarly, on the cold end, once you get below the pain threshold, it’s less about sensing absolute temperature and more about sensing how quickly your skin reaches the pain threshold.

How quickly your skin reaches those temperatures matters. You can hold something that is 400 deg C safely, at least for a while, as long as it has a very low thermal conductivity. It will take the heat a long time to transfer to your skin and heat it up. On the other hand, things with a very high thermal conductivity will burn you almost instantly at those same temperatures. This is how the tiles on the space shuttle work. You can heat the tiles up with a blow torch until they are glowing red hot, but you can still pick the tiles up with your hand because their thermal conductivity is so low.

Between the extreme variance in thermal conductivity of different materials and the body’s poor ability to detect absolute temperature, coming up with any kind of accurate chart is going to be difficult, if not impossible.

16

I disagree with the 110 and 120 levels. 110 is above hot tub temp already, it’s way too hot. Max recommended hot tub temp is listed as 104 degrees and most tubs cannot be set higher then this. 100 to 102 is preferred by most people. As for 120 degree water - I was in a test for this many years ago. I got up to 116 and thought I was going to lose my hand. 120 will definitely scald, it just takes several minutes until the burn develops.

Dennis

17

Here’s an old item from back when we were trying to switch the USA to the Metric system, that might help the OP.

Regarding temperature, don’t bother converting Fahrenheit to Celsius – just remembering a few Celsius temps is enough:

150ºC = baking something in an oven
100ºC = boiling water
37ºC = normal body temperature
20ºC = comfortable room temp
0ºC = water freezes
-10ºC = usual Minnesota winter day
-40ºC = it’s Forty below! In any scale.

18

To tie these together, all surfaces are not alike. Most people have had the experience of touching both metal and plastic at cold temperatures and the metal feels cold and the plastic does not, because the metal sucks the heat out of your skin faster.

But I would have guessed specific heat rather than thermal conductivity–does specific heat matter? Do the two have a proportional relationship?

19

This is how I think of temperature outdoors, only I am interested in the range of outdoor temperatures I encounter in C:

40ºC = too freaking hot
30ºC = uncomfortably warm
20ºC = comfortable room temperature
15ºC = pleasant cool day
10ºC = I’ll want a light jacket
4ºC = temp inside the cool room
0ºC = freezing

I have never been outdoors during below-freezing weather where people used celcius.

20

Air temp vs. water temp are two entirely different things. And the OP doesn’t help sort out things.

I played outside as a kid in 113 degree temp and didn’t notice a thing. “But it’s a dry heat.” Throw in humidity and it’s something else. Make it all water and it’s something else again.