How I pack my cooler to keep electrolytes cold all day

At an Australian summer event, the cooler earns its place beside the ute as surely as Archie’s grooming kit. By the time we leave home, the temperature is already climbing, and a sunny horse float can turn into a moving oven. On a typical outing around Goulburn or between a Melbourne stable and a Ballarat venue, I am managing two kinds of thirst: my own after a long day competing, and Archie’s during warm-ups, jumping rounds, and recovery. The drinks need to stay properly cold without making the float feel like a mobile fridge.

My current arrangement is deliberately simple: chill every bottle, freeze reusable gel packs solid, and use a small amount of loose ice only where it helps most. I pack my cooler with ice packs to keep electrolytes cold all day, while Archie’s measured electrolyte powder stays dry in a sealed container and is mixed with fresh water when needed. That distinction matters. Chilled electrolyte drinks are convenient; leaving horse electrolytes loose and damp in the cooler is not. The rest of this is the packing routine I have refined through hot competitions, long floats, and one too many warm bottles.

Why a tub of loose ice is not enough

Loose ice was my first attempt, and it was not a particularly graceful one. I would buy a bag from the servo near the highway, tip it into the cooler, and hope the bottles were buried in enough ice by noon. Trouble is, ice that has started melting becomes a slushy layer with air gaps around it. The water in the bag keeps things cold, but the bottles can still warm quickly once I lift them out and put them back. The wet, shifting contents also made the cooler awkward to lift and prone to leaking across everything.

What I want from the cooler is predictable cold, not simply cold in theory. The gel packs provide tidy thermal mass that stays in the same place beside the bottles, while a little loose ice fills the awkward spaces and cools the floor of the cooler. I also plan around access. There is no point preserving a beautiful block of ice if the bottle I want at the lunch break is sealed at the bottom under Archie’s buckets. The packing has to work for a tired rider who does not want to excavate half a cooler at an event.

My at-home cooler preparation

My cooler is a 45-litre hard-sided esky with a thick insulated lid and a drain plug at the bottom. That is large enough for the day but still manageable when the ute is loaded and the float is waiting. Inside are two large reusable gel packs, one narrow pack for the centre, a vacuum flask, several sports bottles, a roll of clean tea towels, and a small rubbish bag for empty packaging. I keep the gel packs in the freezer overnight and put the cooler itself in the fridge if there is room. A cold cooler starts the day further ahead than a room-temperature one.

The bottle count depends on the event, but I usually take enough for Archie’s water buckets, my own drinking, and one spare shared between us if the weather turns. I fill all the bottles at home, leave a little space at the top, and use plastic rather than glass. The vacuum flask is for the electrolyte drink I know I will reach for during the cross-country phase, when water can feel surprisingly heavy and the nerves make a cold drink especially welcome. Nothing goes into the cooler in a glass bottle, because it can crack when it shifts against a frozen pack.

How I layer the ice packs

The useful trick is to use the gel packs as walls rather than a single cold layer at the bottom. I stand the narrow pack upright in the middle, arrange bottles tightly around it, and lay the two larger packs along the sides. A folded tea towel goes between the packs and the bottles. The fabric stops the bottles from resting against a freezing surface, absorbs condensation, and keeps small labels from sticking to the plastic. I position the bottle I expect to use first nearest the lid, then fill any remaining gaps with a short block of ice.

Loose ice goes in last, usually on top, where it presses down into the spaces between the bottles and packs. I buy it bagged at the servo because that is usually quicker and cheaper than arriving at an event ground hoping the kiosk sells ice. A ten-kilo bag is more than I need for a local dressage or show-jumping day, so I have learned to ask for a smaller bag or split the load between the cooler and the drinks at home. The drain plug matters once the ice starts breaking up; I can release cold water without opening the whole lid.

Keeping Archie’s electrolytes and water separate

Archie’s electrolyte powder has a different job from my bottled electrolyte drink. I keep the powder dry in its original container inside a sealed plastic tub, then measure it into his bucket with fresh water according to the product label and my vet’s advice. I do not sprinkle it over loose ice or pour it into the bottom of the cooler, where it might settle, stick to the sides, or be spilled when I dig for a bottle. Keeping the powder separate also prevents a scoop from one day ending up in somebody else’s drink.

In hot weather, Archie gets access to clean water throughout the warm-up, between phases, and after his round rather than waiting for one enormous bucket at the end. I place the buckets in the shade, near the horse management area, where he can drink without being crowded by other horses. If a feed calls for electrolytes to be pre-mixed, I make it close to departure in a clean, labelled container and keep that container cool. I prefer fresh water for his main buckets, while the cooler handles the chilled drinks made for people.

Moving the cooler into the venue

When we arrive at the venue, the cooler comes out of the float first and goes under an umbrella or inside the horse management tent. I put it against the side wall rather than directly behind Archie, where a kick could damage it, and use a folded towel beneath it to insulate it from hot ground. The lid stays down unless I am taking a drink or adding ice. Every opening lets warm Australian air into the cooler, so the best cold storage happens when I leave the whole arrangement untouched.

I take my first bottle before the morning warm-up, then keep another at the cross-country start for later. By the arvo, the cooler earns another opening, but I remove one bottle at a time and return everything to its marked position. If the venue has a canteen, I still carry a bottle; queues, a flat battery, or an unavailable ice machine can put paid cold drinks out of reach. On bigger outings, I have bought another bag of ice from the nearest servo and packed it around the bottles that will not be used until the afternoon.

Unpacking and resetting after an event

After the last phase, I unpack the cooler in the shade before loading the ute. Empty bottles and rubbish go straight into the bag, damp tea towels are hung over the float rail, and any loose ice is allowed to melt in the drain plug rather than carried home in a heavy, sloshing cooler. The reusable gel packs go back into the freezer as soon as we arrive home, where they can thaw safely on a rack. I wipe the interior and leave the lid slightly open overnight so trapped moisture cannot create a smell.

The reset is just as important as the morning pack. A dirty cooler opens slowly, cold air escapes around the gasket, and bottles end up sitting beside sticky labels or grit from a previous event. I wash the bottles, air-dry them, and check that the drain plug is seated before the next early start. Keeping reusable packs also reduces the awkward dance of lifting a twenty-kilo bag of ice into the back of a ute. By keeping the cooler tidy, I can pack it in minutes before leaving for the next competition.

Adapting the setup for Australian conditions

Not every Australian event needs exactly the same cooler. In Tasmania, a light pack may be enough for a mild afternoon, while Darwin or a wet Brisbane summer calls for more frozen volume and extra attention to shade. Around Goulburn, the UV can be fierce even when the morning feels pleasant; around Canberra, the dry heat can warm a float quickly; and on a humid NSW event day, condensation forms on every bottle before lunch. I adjust the number of packs, not the basic rule that cold bottles and sealed powder travel separately.

The final test is practical. At a recent summer event, I left before dawn, kept Archie comfortable through dressage and show jumping, and still had cold electrolyte drink waiting after the cross-country round. Nothing looked dramatic; the gel packs were simply doing their job in the right places. That is the arrangement I trust: a cold, organised esky for the drinks, dry electrolyte powder for Archie, and enough shade at the venue to give both of us a fair chance through the Australian day.