I always keep my iPhone in one of my jersey pockets, and find that after long rides it is soaked in sweat and (in the summer months) overheated.
I’m wondering if anyone has a recommended solution to this that isn’t too bulky and doesn’t require a saddle bag.
I’m not too worried about ease of access while riding, but as it shares my location to my wife through my head unit it’s important that the phone stays dry, cool, and operational during the duration of the ride.
I use a quart sized ziploc bag. It’s not sexy, but it gets the job done.
Rapha Essentials Case works well for this (link is the large, there’s a regular as well)…
https://www.rapha.cc/us/en_US/shop/rainproof-essentials-case-large/product/LEC05LRPLK
Big enough for the phone, money clip/thin wallet, and a small keyring without bulging or feeling too thick.
I’ve had a Muc-Off rainproof essentials case, for a little over a year. It fits my iPhone SE2020 with room to spare, has a internal divider to stop the phone getting scratched up by other stuff in the case, an internal zip pocket for key, coins etc. I got the Hi-Viz yellow version so I’d have chance of finding it if it ever bounced out of my jersey pocket which having used it I can’t imagine it ever would.
I got caught out in a storm a couple of weeks ago and rode for almost an hour in the pouring rain with no mudguards, I was soaked through when I got home but the inside of the case was completely dry.
Anyone thinking of carrying their phone in a saddle bag, beware, I used to on my MTB and Gravel bike but discovered that the vibration degrades the internals of the phone’s camera. My daughter had the exact same phone as me and the photo quality was visibly worse on mine despite the lens on mine looking like it was in better condition.
A Phone condom is even lighter than a ziploc bag and sexier
Generally I would say a zip lock bag. However, I recently got the cycling wallet below for when I’m racing and carrying a car key as well (following a crash a few years ago). It fits my S23 in an Otterbox, mini pump, and dynaplug racer tool, as well as my key. With space to spare if you needed to carry a tube/ mini tool.
https://www.amazon.co.uk/dp/B0CCRKVT8S?ref=ppx_yo2ov_dt_b_product_details&th=1
I did have a muc-off one that claimed to be waterproof, but whatever about rain it definitely let sweat through.
Is this a joke or is a “phone condom” a real thing? (Not gonna search that from my work computer)
yes it is a real thing
I have the large version of this one from Waterfield (Grizzly Leather), and it’s hands down the best wallet IMO, and I had bought the Rapha and Silca recycled inner tube wallets (Borsa Eco), and the Waterfield is THE BEST!
It has a rough Cordura side for traction in the jersey pocket, and a leather side for protection, and has padding too. The zippered side pocket is perfect for money, credit cars, passport, and single keys, and the end loop is perfect for removing it at the end of a ride. Being in the back pocket, the leather gets ‘moist’, but doesn’t transfer any of it to the contents.
It has also never slipped out of my jersey, even riding my MTB.
I couldn’t be happier with a ‘cycling’ wallet. (They could make it a smidge larger for those that have the Otterbox Defender case, which is REALLY tight in this case, and just plain too damn big for the other two.
BTW: The big disappointment was the Silca case. I really wanted it to work, but it’s just too small. It’s well made, which made it hard to not hang on to it for other things, but if you have the Pro Max, and don’t go ‘nekud’, AND want to carry other things, skip the Silca. The Rapha kinda fits the Defender case, but it’s far too tight making me think it’s about to explode, ripping the zipper/seams out.
I did use a Ziploc bag, but there are some big issues going ‘commando’. It does nothing to keep condensation from coating everything in it, and there is nothing to keep it from playing projectile out of a jersey pocket. (I ‘lost’ my phone once that way) AND some bags aren’t really durable enough to survive one use, let alone multiple uses. I started wrapping the phone in a ‘lint-free’ cloth, which made the whole thing thicket and, in my mind, making it more likely to escape…
Yeah, zip lock freezer bag for the win, no reason to overcomplicate it. I’ll also throw my car key in there if needed and it’s a good place to keep a few dry napkins to clean off glasses on a rainy day.
Napkins stayed dry? Well, for me, on an easy day maybe. I had some bags also have the seams fail, which was disappointing. I guess YMMV is the rule. For all of it, I gave up Ziplocs and haven’t looked back.
I’ve found a few phones on trails too. At some point there isn’t a way to secure them 100%, except leaving them home, in the car, etc…
Yeah, never had an issue with a ziplock leaking. And I ride/race in the rain and mud pretty frequently (gravel race on Sunday, rained all day). And the sweat of riding in the spring/summer in Texas can get things as wet and nastier than a rain day. Maybe some of those wallets have real waterproof zippers (like a dry suit zipper), but I want something that can basically be submerged without leaking (like a pelican case, but no way I’m putting that in my back pocket).
I used one as well for a while and really liked it. I used to put my phone in 1 case and my toolkit in a second case. Both cases fit neatly into my jersey pockets.
Then I got an Apple watch with cellular because I didn’t want to carry a phone on rides anymore.
I used a heavy duty ziplock bag for years, but after an accident I switched to a Rapha Essential case. The textured case helps to keep the phone (and other items) in the jersey pocket also in extraordinary situations.
Always used a ziplock bag, but I like some of these phone cases! 
I had the original version of the Waterfield and loved it. They even replaced the plastic window over the phone without charge after many years of use. Unfortunately, that repair made the phone sleeve just a hair tighter, and while I could fit my cased Pixel 7a in, it was a struggle to get out. I gave the Craft Cadence wallet a try, and am very happy with it indeed.
In both the Waterfield and Craft Cadence I fit a phone, 3,4,5,6mm hex wrenches, valve core removal tool and spare core, ID, some cash, and a TPU tube. Love grabbing one item that nestles against by back in the center pocket and stays put. No seatbag with clinchers. I do use a Arundel Tubi when riding tubulars, or can use my Relevate Pika for “bigger” rides where I want more spare clothing, or perhaps even my Vibram Five Fingers for time off the bike.
PS. Used zippies etc and some of the early bike-specific zip closure cases, and ride wallets are light-years better.
$59 for a phone case? I’ll stick with my ziplock bags - I use sandwich size.
One time I did get a fancy ziplock style pouch from Assos and I used until the zip part broke. I probably wouldn’t pay A$$O$ prices for one. 
I use that one and use it off the bike too.
I’m fairly happy with this one. A tad bit bulkier than I would prefer but good otherwise.
Thank you to everyone for the responses. I’ve tried ziploc bags in the past with mixed results, but it seems there are a few other options to choose from that fit the need here.