I am travelling with a totally blind diabetic, and a cooler full of beverages (soda). Most of the beverages are diet, but a couple have sugar to treat low blood sugar. The blind person must be able to search in the cooler and find a sugar soda without assistance.
How can the beverage cans be marked so that a totally blind user will be able find one that contains sugar?
Buy drinks with sugar in a non-can format. If there's a bunch of cans, plus 2 plastic bottles, that's easily distinguishable.
What this avoids is having to try each can in turn to see if it has a rubber band or string or whatever. The instant you grab something, it's obvious if it's a can or bottle, which is important when you're having a medical emergency, are blind, and need to plunge your hand into icy water to check each one. It also avoids various failure modes where the marker falls off or breaks. No matter what happens, a plastic bottle is not going to turn into an aluminum can.
Note that these are usually a different size. (20oz vs 12oz.) There are 12oz bottles for sale, though you might need to try a couple stores.
Just a simple thought: you could use a little piece of string tied to the hole in the tab to mark the odd ones out (that's less work than marking 90% of the cans). Like this (it's Friday afternoon, so I have no soda can available):
Low blood sugar (hypoglycemia) for an insulin dependent diabetes is a medical emergency, consuming sugar is a matter of life and death.
The cans containing sugar should be marked, if the marking comes off, accidentally consuming a sugar beverage instead of diet, is much less life threatening
Place a rubber band around the center of the sugar soda cans. It holds up well submerged in melted ice. It can be reused multiple times. It is very easy to feel. A larger rubber band can circle a can a couple of times. Occasionally they do break so make sure there are always a couple of them in the cooler.
This is the current solution used by my blind companion, but there are some interesting ideas we had not considered in the other answers.
There are many good answers here. I'd use that old lifehacks fallback: duct tape. Just wrap a band of duct tape around the middle of every soda that includes sugar. It will be an easy, tactile way to identify cans containing sugar.
Braille labels are available — some of them are made specifically for cans.
A blind person without the help of a sighted person can take advantage of the difference in density between diet and sugary drinks. Diet sodas cans float in water; regular soda cans sink.
Is it beyond the realms of possibility to just put the sugar containing drinks cans inside a plastic sandwich bag, ziplock, whatever and tie the top? 2 cans in plastic bags in the cooler doesn't matter if you can see or read braille or not. Foolproof and safe, and you will be able to recycle/reuse existing plastic bags and thus save a dolphin.
if the cans come in a linked 6-pack, cut up the "linker" that ties them together and leave it on the ones you wish to mark.
Or, bend the pull tab partway up on the ones you wish to mark.
Put the sugary cans in a plastic tub inside the cooler.
For example:
A huge benefit to this method is that the person doesn't have to feel the cans one by one. Just find the tub. You need to use an appropriate shape to reduce the risk of cans rolling in or out.
You can stick a label onto the top/side of the tub to remind others not to put other drinks in it.
or
Use a different sized can
A standard treatment for low blood sugar is typically around 15g of carbs whereas a standard soft drink (soda) can has around 38g. In Australia we have multiple can sizes including 200mL which has about 20g of carbs. That works well for me. If smaller cans are available where you are, you could ensure they are exclusively full-sugar.
This depends, of course, on what protocol the person uses for treating hypoglycæmia.
or
Use rubber wristbands
They don't need to have anything written on them. They're just prettier than rubber bands or duct tape. You could also put a message on them (the person's name perhaps) to stop them being drunk by others.
when planning for emergencies try to make the protocol very easy (were the ones with a thread sugar free or with sugar?) ...
Some totally crazy ideas:
get two coolers! one for the blind person close to them, so it is easy to find.
all of you drink sugary drinks, no confusion, all are happy (sugar replacements are allegedly cancer inducing anyway)
get another source of sugar that is easily digested (have no experience, dextrose maybe?)
mixing up some answers: attach a metal or plastic braille plate with duct tape to each can (you can reuse them on the next trip)
cable zip ties could help too instead of a string.
contact beverage manufactures to include braille code in the can, like you have on medicine boxes. It could be on the bottom, top or walls. non-blind people might even start reading braille if they are exposed all the time.
Requiring no additional resources, and better than @niels-nielsen's suggestion (which risks breaking the tab or seal by pulling):
Rotate the tab 90 degrees for the desired type of drinks. The top has a recess in which the tab sits that a blind person can use as the reference.
Note: if a blind person can read braille, they can easily detect the recess and the orientation. The tab is also non-free spinning; it requires moderate effort to rotate to a position, where it will stay until rotated again, so it will not accidentally move back.
We do that to distinguish otherwise identical beers in the locker room after the game: L, C, R.
Ideally, you'd use a device that can make Braille labels. As an alternative, there are devices that make embossed labels - but you'd have to agree on what encoding to use (e.g. 3 dots for drinks with sugar, one dot for no sugar).
This answer is based on two already given but too much for just a comment.
Mark all cans (as given in @Glorfindels answer) but use different kind of string for with and without sugar. Cotton against wool will already do.
Add a tag to the end of the (short) string, many kinds of plastic can be cut into usable tags. You only need a way to tie the string to it.
Many kinds of plastic will allow you to add some braille to it, a few characters at least and if you hit the right kind of plastic maybe enough to write the whole name of the drink. (This part is based on @Hobbes answer.)
To make it easy for the seeing users of the cooler, use different colours for the string as well. Like red wool for sugar containing drinks and white cotton for those without, so when picking out a drink for your companion, you can see immediately which category you catch.
Consider another option.
Use glucose tables for the quick treatment of low blood sugar. Chew it into powder and keep it under your tongue for quick absorption.
He should have talked to his Dr about it. It is a standard part of managing the disease.
Diet... Exercise... Meds...
It's cheap. One can break a tablet into 1/2 or 1/4 depending on the Blood Sugar Level.
Here is a link to a site that sells it. Pretty much all drug stores carry it.
https://www.walgreens.com/store/c/walgreens-glucose-tablets-grape/ID=prod6181254-product
To add another 0.02, I'd use a pair of pliers to apply a small twist deformation to the rim of the can (at some position that won't touch the mouth or the nose)
This can be easily felt, cannot be removed (like stickers, rubber bands etc), manipulated by a guest (an ocd type who will reset all the rotated ring pulls), is quicker to apply than other manipulation resistant methods (tying string) mentioned and is more discreet (no one will take notice of can damage, but they might mess with a rubber band)
I'm not sure whether I'd mark the sugary cans or the non sugary ones; it's for you to decide I guess. This method can't be undone by accident and I find it likely that a blind person would be able to feel the difference between a can that had been twisted with pliers versus one that had a damaged rim from being dropped so really you're asking whether it's better to mark the sugary ones because if you miss one then you have a sugary drink that will be ignored (isn't a hyperglycaemic bomb) or mark the diet ones because they're low in number and you're highly unlikely to mark a sugary one. The fail safe will be based on your confidence in the accuracy with which you can complete your task of marking the cans plus how likely you think accidental damage could be mistaken (if you mark all the sugary cans and someone damages a non sugary in the exact same way then you risk hypoglycaemia instead of hyperglycaemia; it's easier to treat hypo than hyper because sugar is more widely available than insulin). Personally I think I'd mark the sugar ones.
ps; I say pliers but actually any device with a slot in it just wider than the width of the can (think of a very small spanner) could apply a twist. Additionally your fingernail, back of a knife etc would be able to make a repeated crease in the shoulder of the can (where the can widens out after the rim then transitions to a vertical cylinder) that could be felt, and cans would also be quite likely to survive the rim or base (where it contacts the desk) being dented with a pattern (such as three in a row) that could be applied by any sharp, hard object such as car keys or even the rim of another can (thus marking two at the same time)
In this latter case of getting more adventurous with deforming the can, maybe make it the sugar free ones you damage, as it's a lot less sticky if you have to clean up after bursting one. They take a lot of punishment in transit though so I think you'll be fine if careful
How to mark beverage cans in a cooler for a blind person?
When in Rome do as the Romans do!
When traveling with the blind do what the blind do! Read braille. One the bottom of the can put a drop of krazy glue on the bottom of the can. Keep in mind what the number of dots mean. There is enough room on the bottom of a can for up to 10 +/- dots. Put the code to memory of on paper in your memory is not good.
Why would you want to store an emergency sugary drink in the cooler? The last thing you want to do close to hypoglycaemic shock is to expend the calories for heating a drink to body temperature and have your stomach cramp up and not let it pass. Just place it somewhere obvious outside of the cooler.
