Fed up of burning yourself on hot oven dishes which look the same as cold ones? Print warnings on the dishes in a heat-sensitive ink so they'd say "HOT!" in big red letters when they're hot, but fade out as the dish cools down. The same thing could be done on electric hobs.
Updated July 17th -- I'm almost overcome with emotion at how many votes this humble idea has attracted. Judging from others' comments it looks like this sort of thing has been done before (I remember "global hypercolour" heat sensitive clothing) but the problem is that the colour change becomes permanent after a while or after a certain number of heat cycles. Maybe, using our modern mass micromanufacturing abilities, we could manage the colour changing with an array of microscopic bimetallic strips. As they heat up they curl over and expose a different coloured side, then straighten out again as they cool. Obviously they would have to be protected from dirt and moisture by some sort of clear covering which would not interfere with their bending.-- Skinny Rob, Jul 14 2000 Online dictionary for egnor http://dictionary.msn.com/ [Lemon, Jul 14 2000, last modified Oct 05 2004] Cold enough to... http://colitz.com/s...4634021/4634021.htmThe oppsite to Reensure's chickensticker... [StarChaser, Jul 14 2000, last modified Oct 05 2004] BASF http://sites.netscape.net/sgr2/m/m2.htmIt falls to the welldigger [reensure, Jul 14 2000] Thermospot frying pan http://www.emccord....PUM00A3HBNRWAUDG54TAlmost baked. These frying pns have a dot which turns bright red at the ideal frying temperature [hippo, Jul 14 2000, last modified Oct 05 2004] Temperature Sensitive Mugs http://www.idea-exp...lassware_mystic.htmI remember getting one of these for my dad during the total solar eclipse in Hawaii. [wtanaka, Jul 14 2000, last modified Oct 05 2004] Color-changing plastic spoons http://www.addedtou...p?number=1152U&s=ga [jutta, Feb 17 2006] Thermochromic urinal. http://tumblr.matri...ooler-than-this-oneThis thermochromic thing seems to be catching on. [DrBob, May 04 2011] Design: William Spiga & Juliana Martins, Coral (2009) https://www.yankode...colors-for-cooking/IDEA Brasil 2009 - finalist, written up a bit, never actually produced, as far as I can tell. [jutta, Jan 31 2023] Reddit thread: Why isn't this more popular? (2020) https://www.reddit....e_not_more_popular/A: because most people don't burn themselves often enough to make it profitable? [jutta, Jan 31 2023] Color Changing Whirley Pop https://www.wfarms....no-popcorn-includedStovetop popcorn maker that changes color as it heats up [swimswim, Feb 01 2023] What's a "hob"?
(I see: it's a "burner". I think our name is more descriptive than yours. So nyaah.)-- egnor, Jul 14 2000 See link to left. Although having said that, their definition of "hob" is inaccurate by modern European English usage, where it (now) means the hot metal plate, or gas ring on which you place saucepans, frying pans etc, in order to heat their contents. Alternatively the kitchen unit in which several of these devices are set.
(pfah! Typical you should use a word with double the number of syllables! <sticks out tongue>)-- Lemon, Jul 14 2000, last modified Jul 17 2000 You should already be able to find heat reactive stickers that say STOP or HOT (or both) when the surface under them would scald or burn. My dad used to have one on cover of his grill, ostensibly to keep his foolish children from branding themselves.
After heating and cooling a number of times over a period of months the sticker seemed to remain in the activated state, which I guess is a good default setting.-- centauri, Jul 14 2000 Some Japanese teahouses already use this technology. The serve tea in cups with a bright blue, patterned, thermoreactive glaze that appears and reappears with changes in temperature. Also some handblown, artsy-fartsy smoking implements, like pipes/waterpipes, have temperature reactive glass in them. They become progressively more opaque (white or blue) the more they are heated, and the color will disappear completely if the object is boiled and/or reboiled. (I don't know how it works, though.)-- naveline, Jul 15 2000 My son's 'Tommee Tippee' Tableware (he's six months) are made from thermochromic plastic (red in cool state - yellow if over safe heat for small children). Especially good for spotting how hot it's got in the microwave.-- goff, Jul 17 2000 Perhaps McDonald's (or other places with insanely-hot coffee) could use color-change chemicals on their coffee cups? I remember a gas station in Pennsylvania were I filled a 20oz coffee cup about 2/3 full, added twelve creamers (6 oz total), and blew through the coffee with a straw for 20 minutes, and it was still too hot to drink! Too bad the ice machine was broken...-- supercat, Jul 19 2000 Was the coffee worth it after all that?-- eagle, Jul 19 2000 Reensure: <grin> No, you weren't speaking in legalese...I just thought something to show extreme cold as well as hot would be cool, and this was greatly amusing...-- StarChaser, Jul 20 2000 I bet if one could make a kitchen wrap on a roll, with these properties, they would make a bundle. Cover your dinner with a foil that changes color when the porkchops have been hot enough for long enough. Solves the concern over wheather multiple uses would invalidate you color changes. Can be used with plastic wrap in the fridge too. If for some reason the icebox has allowed your frozen fish to rise to an unsafe temperature for too long, then then a picture dissapears or the wrap changes colors.-- interpreter, Jul 25 2000 I discovered to my chagrin that the skin on my hands is themochromic....I lifted a dish straight out of the oven and my skin turned red then returned to pink as it cooled....If it didn't hurt so much, this would be a very usefull feature....I'll use a tea-towell next time maybe...-- Haemavore, Sep 24 2000 what the h*** is a tea towell? as far as I know, towel only had one l. must be an English thing.-- DreamGoddess, Nov 29 2000 A tea towel (one l) is a thin towel used for drying cutlery and crockery. I suspect you may call them dish cloths, which are something different in the UK.-- Lemon, Dec 04 2000 eagle: The coffee wasn't all that great, but with hours of driving to go [friend's funeral] it sufficed.-- supercat, Dec 11 2000 Interpreter - I think the fish part of your idea is already used for vaccines. If the cold chain is broken and the vaccine gets too hot then a warning appears telling the medics that the vaccine is useless.-- Gordon Comstock, Dec 21 2000 Sorry to drag you guys back on topic - While you've been discussing teatowels I've been busy. See link.-- hippo, Jan 22 2001 What a wonderful idea. I'm always such a clod in the kitchen-- this would save me some skin.-- kitsune, Apr 13 2001 random, halfbakery