Altitude and environment

Altitude and the record book: the “A” annotation

World Athletics' official Terms and Abbreviations document defines the code "A" as "Altitude (over 1000m)" — a real, primary, precisely thresholded convention. What it is not is a ratification condition: a full reading of the Competition Rules' Part III (World Records) finds no altitude provision at all. The only "1:1000" figure anywhere in that Part concerns a road course's permitted overall elevation decrease, a different concept entirely from atmospheric altitude. A mark set above 1,000m is ratified as a world record on exactly the same terms as any other mark; wind is the regulated condition (a sprint or jump record is voided above +2.0 m/s), altitude is not. Put simply: athletics discloses altitude for statisticians' benefit, it does not penalize it.^[1] [2]

Mexico City sits at 2,240m, per World Athletics' own description of "the thin air of Mexico City's helpful 2240m altitude." Bob Beamon's 8.90m long jump on 18 October 1968 — with a wind reading of exactly +2.0 m/s, the maximum allowable — beat the previous world record by 55cm and stood as a fully ratified record for nearly 23 years, until Mike Powell's 8.95m in 1991. World Athletics states "no less than nine world records" were set in the men's events at those Games, including Jim Hines' 9.95 in the 100m (the first sub-10 mark with electronic timing). Every one of those marks remains a ratified world record on the day it was set, regardless of altitude. Whether World Athletics' own results database applies the "A" annotation to these specific 1968 entries could not be confirmed in the research behind this page — the code's definition and threshold are verified; its application to any one historical entry is not, and this page does not assert it.^[3] [4]

Altitude and eligibility to play: FIFA's 2007–2008 ban and reversal

Athletics discloses altitude without penalizing it; football, briefly, penalized it outright. On 27 May 2007 FIFA's Executive Committee prohibited international matches above 2,500m, citing medical concerns for players and an unfair home advantage for highland teams, with acclimatisation requirements scaled to altitude.^[5] On 27 June 2007 FIFA raised the threshold to 3,000m, removing Bogotá (2,650m) and Quito (2,800m) from the prohibition while leaving La Paz (3,600m) barred; FIFA President Sepp Blatter stated the ban applied only to World Cup qualifying matches.^[6] La Paz reportedly received a special exemption at a subsequent FIFA meeting, though the exact date and character of that step could not be confirmed and is treated here cautiously rather than as settled fact.^[7]

On 29 May 2008, FIFA's Executive Committee unanimously agreed to suspend the altitude ban following a formal CONMEBOL protest supported by every South American member association except Brazil; Blatter's position was framed as reopening the discussion rather than conceding error. The ban was never reinstated — by 2010 Blatter said altitude was "not on FIFA's agenda," and high-altitude associations have hosted internationals without restriction since. Estadio Azteca (2,240m) hosted matches at the 2026 World Cup with no altitude restriction in force, which revived public discussion of the episode.^[5] The Bolivian government under Evo Morales had campaigned publicly against the original restriction, an episode academic literature has treated as an example of sport becoming entangled in domestic politics.^[8]

Heat: WBGT and the threshold regimes

Wet Bulb Globe Temperature (WBGT) — a composite index of temperature, humidity, radiant heat and wind, distinct from simple air temperature — is the most common heat metric across federations, but "uses a WBGT threshold" describes several genuinely different regimes. World Athletics states that its Competition Medical Guidelines "recommend that mitigation measures should be implemented in endurance events where the WBGT measure is over 28°C" — language confirmed in the federation's own release on the Doha 2019 50km race walk, where the women's marathon was run in conditions of 28°C–30.9°C WBGT. Critically, that 28°C figure triggers mitigation, not automatic cancellation: the decision to alter a start time or withdraw an athlete rests with the Medical Delegate's judgment, not a fixed number. World Athletics publishes no comparative WBGT threshold table across federations, and its own endurance-medicine research acknowledges that "thermal indices currently used do not completely represent the thermal strain endured by athletes."^[9] [10]

FIFA's 2014-era rule set a genuine WBGT trigger of 32°C for a three-minute cooling break, at referee discretion. That threshold no longer applies at FIFA's flagship tournament. On 7 December 2025 FIFA abolished it for the 2026 World Cup, making three-minute hydration breaks in each half unconditional in every match regardless of temperature — FIFA's own release states "there will be no weather or temperature condition in place." The global players' union FIFPRO has separately recommended a lower 26°C WBGT threshold for mandatory breaks and 28°C or above as a postponement threshold, plus extending half-time from 15 to 20 minutes — the only published postponement number in football, and it comes from the players' union rather than the federation.^[11] [12]

Tennis illustrates a federation moving away from WBGT rather than adopting it. The Australian Open used a WBGT threshold (28°C from 2003, later revised to 32.5°C) through 2018. For 2019 Tennis Australia replaced it entirely with its own proprietary AO Heat Stress Scale, a 1–5 index developed with the University of Sydney's Thermal Ergonomics Laboratory, measuring air temperature, radiant heat, humidity and wind speed at five locations across Melbourne Park in real time; at a reading of 5.0, matches on outer courts may be suspended and roofed-court play pauses for the roof to close. On 24 January 2026, roofs were closed and outdoor matches suspended as the tournament recorded 36°C ambient conditions — the specific Heat Stress Scale reading behind that call was not confirmed in the sourcing for this page.^[13] [14]

Heat: relocation and rescheduling as the real remedy

Where a numeric threshold triggers mitigation rather than cancellation, the practical remedy federations reach for instead is moving the event — in time or in place. At Doha 2019, the IAAF World Championships ran its marathons and race walks at midnight because of the region's daytime heat; the women's marathon was still contested above World Athletics' own 28°C mitigation threshold. The IOC cited that Doha experience directly when, in October 2019, it relocated the Tokyo 2020 marathon and race walk roughly 800km north to Sapporo over the host city's own objections — the clearest example in this topic of environmental conditions overriding a host city's contracted Olympic programme, decided less than a year before the Games. For hosting decisions made at the bid stage rather than after award, see hosting and bidding.^[9] [15]

Paris 2024's heat response centred on schedule design and village cooling — the Olympic Village was built without conventional air conditioning, a decision several delegations, including Team USA, overrode by importing their own units — rather than any published WBGT threshold or formal heat-postponement rule; no such Paris 2024 document was located in the research behind this page, and none should be assumed. For Los Angeles 2028, no primary IOC or LA28 document setting out heat protocols or thresholds has been published as of September 2026; the available material is anticipatory academic and journalistic commentary rather than adopted policy, and this page treats LA28's approach as unresolved rather than assuming one exists.^[16]

Air quality: no federation-level threshold to report

Every documented air-quality case in this research was handled by ad hoc decision, not against a published international-federation rule. On 7 June 2023, MLB postponed games at Yankee Stadium and in Philadelphia as North American wildfire smoke pushed the Yankee Stadium Air Quality Index to 335 ("hazardous"); MLB's own statement described the call as following "conversations throughout the day with medical and weather experts," not the application of a numeric league rule. Beijing's approach to the 2008 Olympics was pre-emptive rather than a postponement mechanism: roughly two million vehicles per day were taken off Beijing's roads between 1 July and 20 September 2008, and over 200 factories were relocated — mitigation aimed at avoiding the problem rather than a threshold for calling off an event once it arose; marathon favourite Haile Gebrselassie nonetheless withdrew from the Olympic marathon over air-quality concerns.^[17] [18]

Where numeric air-quality postponement thresholds do exist, they are domestic and sub-elite rather than set by any international federation. The Mid-American Conference's rule, effective 14 August 2023, is the most fully specified found in this research: at an Air Quality Index of 201 or above during competition, "competition shall be halted immediately," with the conference Commissioner holding sole authority to cancel, postpone, reschedule or terminate a contest. The Road Runners Club of America's guidelines similarly call for "100% cancel the event" above an AQI of 201, and the California Interscholastic Federation applies narrative breakpoints at AQI 100 and 150. No comparable numeric rule was found at international-federation level for any sport — the gap between domestic specificity and international silence on air quality is itself the notable pattern here, not an oversight in this page's research.^[19] [20]

Water quality: the one published threshold regime, and where it has failed

Water quality is a different medium from the air and heat conditions above, but it is the closest thing in this whole topic to a clean, numeric threshold-to-postponement mechanism, so it is included here rather than on a separate page. World Triathlon and World Aquatics both publish bacteriological water-quality categories for open-water and triathlon swim legs, expressed as colony-forming units of E. coli and enterococci per 100mL of water — the specific published figures are not reproduced on this page because the only secondary source located for them was internally inconsistent, and the authoritative numbers should be read directly from the World Triathlon Competition Rules rather than taken from this summary. In January 2025 World Triathlon relaxed its swim water-quality standard, moving the acceptable level for enterococci and E. coli from the "excellent" category to the "good" category and changing its decision process to involve multiple parties rather than one individual — a federation loosening an environmental threshold in the cycle immediately following a Games at which that threshold had caused repeated postponements.^[21]

The men's Olympic triathlon at Paris 2024 was postponed on 30 July 2024 because of elevated E. coli levels in the Seine and run the following day; the Paralympic triathlon events were also postponed by roughly a day over the same issue in early September 2024, and the pattern predated the Games themselves — an August 2023 pre-Olympic test triathlon had its swim leg scrapped over Seine pollution, as was a 2024 test event for the Olympic marathon swim. A further, non-Olympic precedent: events at the July 2025 World Aquatics Championships in Singapore were also postponed over poor water quality, though the specific readings and threshold applied there could not be confirmed in this research.^[22] [23]