climbing in serious cold is one thing, and climbing in serious heat is another. ‘serious’ here means the process of climbing is changed due to the direct effects of heat, and like serious cold can damage tissue and compromise ability.

50c / 122f at the rock’s surface: hot enough to limit the amount of time contact can be made with the rock

today’s session was expected to be hot, so it was planned to be over by midday. a degree of discomfort was factored in, but antidotes like water, sun cream & shade were included.

but, by 11:00am the heat coming off the rock was hitting 50c, making it too hot to touch, and we called it early. consider that to be radiating at 50c the actual surface will be hotter. consider too that to a tenderloin steak is cooked at 55c, for less than an hour. its not enough to kill bacteria but it is enough to break down the fats, collagen and protein to make them digestible and be released as juices.

heres what climbing in 50c entails:

  • reflected heat onto the front of the body feels like an open oven. unlike direct sunlight, its not from a single direction, so hits all surfaces

  • above about 45c the heat is felt straight thru the rubber of climbing shoes, even thicker stuff like the rand of TC Pros

  • around 50c the heat on the toes can only be tolerated for about 10mins

  • temperatures like this massively soften the rubber, nice for sensitivity, painful otherwise

  • finger contact, especially open handed, is limited to about 1 min. that most holds face sun-wards compounds the problem

  • any metal device getting friction (belay / rappel devices etc) get hotter than normal and take longer to cool. they certainly get hot enough to burn skin, and sizzle when water or sweat is dropped on them when rappelling.

  • any hard dark surface gets really hot, including helmets, shoe rubber, the insoles of shoes left at the base of the route, buckles, pitons etc

  • any water carried gets hot fast unless frozen first

essentially, the combination of radiated and reflected heat from the rock creates a zone maybe 1m deep over the rocks surface that is habitable for only short periods. the rock itself is possibly significantly hotter. like intense cold, a degree of adaption with the right actions can be achieved, which would include:

  • wear full coverage, reflective coloured clothes. especially for any jamming arete route where large areas of the body contact the rock

  • cover every skin surface with sun cream, including downwards facing areas like inside the nose, under the chin, backs of legs

  • consider easier route options that minimize prolonged static positions

  • consider the rock type: lighter rock stays relatively cooler but reflects more. darker rock is obviously hotter.

  • on harder routes plan around areas of shade and consider aiding, even just for rests, to reduce contact with the rock surface

  • wear larger sized rock shoes to give extra buffer from pushing against hot rock

  • carry water on route – delaying hydration even slightly when inside a zone of 50c gets dangerous fast. supplement with electrolytes. stuck on a rock wall is not a good place to be when the effects of dehydration or hypernatremia hit.

  • consider a gri gri for belaying – the part-plastic construction reduces the chance of burns over an ATC or all-metal device like a cinch

  • use gloves for belaying and rappelling. anything that normally gets hot will get hotter and remain hot longer

  • factor for much longer times…

…this session was meant to be 14 x 25m pitches at 5.8 to 5.10, expected to take 2 hrs. instead it took 1.5hrs to do 5 pitches, then we called it. rather than 5 or 6 pitches back to back, each pitch required a prolonged rest between to hydrate, allow metal gear to cool from the rappel off and boots to be cooled. really.

consider too: daytime peak temperatures were expected at between 1:00 and 2:00pm. if it was hitting 50c at 11:00am….

seriously, climbing in intense heat involves limited fun. on big routes, entering conditions like this for more than an hour or so could get nasty fast. unlike intense cold where options can exist for retreat into sleeping bags, shared body heat etc, retreat from serious heat is at the mercy of what the route offers. when the hottest zone extends several feet off the rocks surface, the shade of a portaledge may help, but the radiated heat will still be huge.

its funny how the suffering from intense heat makes one long for the suffering of intense cold that seems so far away…