# Livestock Heat Stress Preparedness Plan ## Key Takeaways - A proactive Livestock Heat Stress Preparedness Plan is essential, utilizing pre-defined Temperature-Humidity Index (THI) forecast triggers specific to species and production stage to initiate interventions before critical thresholds are breached. - Environmental modifications, including provision of adequate, well-ventilated shade (reducing solar radiation by at least 50%) and ensuring continuous access to clean, cool water (below 25°C) at sufficient points, are foundational to mitigating thermal load. - Operational adjustments such as shifting handling and feeding schedules to cooler hours (early morning/late evening), minimizing exertion during heat events, and increasing the frequency of direct animal observation for clinical signs (panting, drooling, recumbency) are critical. - Robust emergency communication chains and meticulous record-keeping, logging THI, interventions, animal losses, and treatment outcomes, are vital for evaluating plan effectiveness and refining future preparedness strategies. - Nutritional adjustments, such as increasing dietary fat and reducing crude fiber in pigs, or offering higher concentrate rations in ruminants during heat stress, can reduce metabolic heat production, but require nutritionist consultation to prevent acidosis. - Vulnerable production stages, including lactating animals, young stock, and gestating sows, require tailored strategies, such as adjusted marketing weights, reduced stocking densities, or targeted cooling, to minimize adverse impacts on welfare and productivity. --- A livestock heat stress preparedness plan is a systematic set of protocols to reduce thermal load on animals and maintain performance, welfare, and survival during periods of elevated ambient temperature and humidity. The plan relies on pre,defined forecast triggers, physical modifications to the environment (shade, water, ventilation), alterations in handling and feeding schedules, intensified observation, documented emergency communication chains, and record,keeping to evaluate effectiveness and refine future actions. These components are derived from standards and guidance published by the World Organisation for Animal Health ([WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/)), the Food and Agriculture Organization ([FAO Animal Production and Health](https://www.fao.org/animal-production/en/)), and the United States Department of Agriculture ([USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease)), as well as species,specific reviews in the [Merck Veterinary Manual](https://www.merckvetmanual.com/) and recent literature (e.g., [Livestock production system management responses to thermal challenges](https://api.elsevier.com/content/abstract/scopus_id/36448979593), 2007, [Heat stress and goat welfare](https://api.elsevier.com/content/abstract/scopus_id/85103491888), 2021). The plan must be adapted to species, production stage, facility design, and local climate, no single set of triggers or measures fits all operations. ## At a Glance | Element | Key Action | |---------|------------| | Forecast triggers | Use local weather data to activate plan when temperature,humidity index (THI) crosses a pre,set threshold for the species. | | Shade | Provide sufficient, well,ventilated shade (natural or artificial) that does not trap heat or restrict air movement. | | Water | Ensure clean, cool water is continuously available at enough points to prevent competition. | | Ventilation | Maximize air flow (natural or mechanical) to remove heat and humidity from animal pens. | | Handling changes | Minimise movement, restraint, sorting, and transport during heat events, shift feeding to cooler hours. | | Observation | Increase frequency of checks for panting, drooling, staggering, and recumbency. | | Emergency communication | Pre,establish a contact list for veterinary assistance, utility repair, and animal transport. | | Records | Log THI readings, actions taken, animal losses, and treatment outcomes for plan review. | ## System Context and Planning Decisions Heat stress occurs when the total heat load (from the environment plus metabolic heat production) exceeds an animal’s capacity to dissipate heat. The physiological response includes increased respiratory rate, elevated body temperature, reduced feed intake, and altered blood flow distribution, all of which can depress growth, milk yield, reproduction, and immune competence. Planning decisions must consider species and breed differences: for example, Bos taurus cattle are more susceptible than Bos indicus, and heavy finishing pigs are more vulnerable than lighter growing pigs. These genetic and management,related differences are documented in reviews such as [Genomic responses to climatic challenges in beef cattle](https://api.elsevier.com/content/abstract/scopus_id/85202943555) (2024) and [The effect of climate change,induced temperature increase on performance and environmental impact of intensive pig production systems](https://api.elsevier.com/content/abstract/scopus_id/85095988324) (2020). Additionally, low, and middle,income settings may require simplified adaptation strategies that rely on low,cost shading and adjusted working hours ([Simplified climate change adaptation strategies for livestock development in low,and middle,income countries](https://api.elsevier.com/content/abstract/scopus_id/105004451164), 2025). The decision to implement a heat stress plan should be a standing operational protocol, not a reactive measure. The plan’s triggers should be derived from local meteorological records and the known THI thresholds for the species and production stage. Veterinary consultation is required to interpret ambiguous signs, especially when concurrent disease or poor body condition may mimic or compound heat stress. Records from previous heat events (e.g., [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) surveys) can guide the choice of trigger levels and the frequency of observations. ## Core Management Framework The framework integrates five interlocking domains: environmental modification (shade, water, ventilation), operational adjustment (handling, feeding), animal observation, emergency communication, and documentation. Each domain must be assigned to a responsible person and rehearsed before the heat,stress season. Uncertainty about the precise timing or severity of a heat event should lead to earlier activation instead of delay, the cost of a false alarm is lower than the cost of a mortality event. When signs of advanced heat stress (e.g., severe panting, unsteadiness, vomiting) appear, immediate cooling measures (wetting, moving to shade) and veterinary contact are mandatory. ### Facilities and Environment Effective heat stress mitigation begins with the physical environment provided to livestock. Shade structures are the first line of defense. The [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) guidance emphasizes that shade should reduce solar radiation by at least 50 percent and be positioned to allow airflow underneath. Permanent shade cloth with 80 percent blockage is common, but orientation relative to prevailing winds is critical to avoid trapping hot air. For housed animals, [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) resources note that natural ventilation should be supplemented with mechanical fans when airspeeds fall below 1.5 meters per second at animal height. Tunnel ventilation systems, where air is drawn through the barn lengthwise, are particularly effective in swine and poultry facilities. Evaporative cooling pads reduce ambient temperature by 5 to 10 degrees Celsius but require careful management of humidity, as excessive moisture can worsen heat load in ruminants. Outdoor systems benefit from portable shade structures or access to wooded lots. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) advises that shade area per animal should be calculated based on expected solar exposure duration, also peak temperature hours. For cattle, 3.0 to 4.5 square meters per head is typical, though this varies by breed. Concrete or compacted earth surfaces under shade should be wetted periodically to promote evaporative cooling from the ground. However, standing water and mud increase risk of foot rot and mastitis, so drainage must be adequate. Sprinkler systems that deliver large droplets and wet the animal’s coat instead of the air are effective for cattle and swine, the [Livestock production system management responses to thermal challenges](https://api.elsevier.com/content/abstract/scopus_id/36448979593) review (2007) confirms that intermittent sprinkling (e.g., 1 to 3 minutes on, 10 to 15 minutes off) reduces core body temperature without saturating bedding. Ventilation failures, whether from power loss or mechanical breakdown, must be addressed in the plan. [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) standards on animal welfare specify that backup generators should be tested weekly during hot seasons and have a fuel supply sufficient for 48 hours of continuous operation. Alarm systems that notify personnel when barn temperatures exceed a pre-set threshold are recommended, with cell phone or radio contact as backup. ### Nutrition and Water Water intake increases two- to threefold under heat stress. [PubMed record 42141240](https://pubmed.ncbi.nlm.nih.gov/42141240/) documents that lactating dairy cows may consume up to 30 percent more water when ambient temperature exceeds 30 degrees Celsius. Trough space and flow rate must accommodate this demand, the [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) guidance recommends at least 5 centimeters of linear trough space per head for cattle and 2.5 centimeters for sheep and goats. Water should be shaded or insulated to prevent heating above 25 degrees Celsius, as warm water reduces intake. Electrolyte supplementation may be warranted, but [PubMed record 41530826](https://pubmed.ncbi.nlm.nih.gov/41530826/) cautions that sodium and potassium levels must be balanced with diet composition to avoid ruminal acidosis or hyperkalemia in swine. Feed composition adjustments can reduce metabolic heat production. The [The effect of climate change-induced temperature increase on performance and environmental impact of intensive pig production systems](https://api.elsevier.com/content/abstract/scopus_id/85095988324) (2020) study shows that increasing dietary fat by 3 to 5 percent and reducing crude fiber in grower-finisher pigs lowers heat increment by 8 to 12 percent. For ruminants, shifting feeding to cooler hours (early morning and late evening) aligns with natural grazing behavior and reduces diurnal heat load. [PubMed record 41375413](https://pubmed.ncbi.nlm.nih.gov/41375413/) reports that feeding a total mixed ration with higher concentrate proportion (60 to 70 percent) during heat stress maintains dry matter intake in dairy cows compared with high-forage diets. However, producer should consult a nutritionist to avoid subacute ruminal acidosis. In goats, [Heat stress and goat welfare: Adaptation and production considerations](https://api.elsevier.com/content/abstract/scopus_id/85103491888) (2021) notes that browsing species may reduce feed intake by up to 40 percent when ambient temperature exceeds 35 degrees Celsius, offering palatable, high-moisture forage such as silage can partially compensate. ### Production-Stage Decisions Reproductive and lactating animals are most vulnerable. [Genomic responses to climatic challenges in beef cattle: A review](https://api.elsevier.com/content/abstract/scopus_id/85202943555) (2024) indicates that embryo transfer and timed artificial insemination during cooler months improve conception rates compared with summer breeding. For poultry, the [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) data show that mortality rises faster in broilers older than five weeks, thinning flocks earlier or reducing stocking density by 10 to 15 percent during heat alerts can preserve welfare. In swine, gestating sows are often moved to cooler pens or provided with drip cooling on the snout and neck. Weaning piglets during periods of sustained heat above 30 degrees Celsius is inadvisable because weaning stress compounds thermal stress. Growing and finishing animals require attention to growth rate reduction instead of immediate survival. [Simplified climate change adaptation strategies for livestock development in low-and middle-income countries](https://api.elsevier.com/content/abstract/scopus_id/105004451164) (2025) argues that adjusting marketing weight to a lower target during hot months can reduce days on feed and associated heat load. For lambs and kid goats, access to creep feeding areas with supplemental shade and water outside the maternal pen reduces competition. ### Records and Monitoring A comprehensive heat stress plan requires systematic record keeping. The [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) recommends daily logging of temperature and humidity at animal height, along with a calculated temperature-humidity index. Thresholds for action are species-specific and should be defined based on local climate and breed tolerance. Records of mortality, morbidity, feed and water intake, and behavioral panting scores provide trend data to refine triggers. For example, a 5 percent drop in feed intake over two days in a dairy herd warrants preemptive measures before clinical signs become evident. The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) surveys indicate that farms with written heat stress protocols and daily monitoring logs experience 20 to 30 percent fewer heat-related deaths compared with those without. Recording the timing and duration of interventions is equally important. If sprinklers are activated at 0800 hours, whether they were turned off at noon or continued until evening should be noted. This information is used to adjust the plan seasonally. ### Welfare Considerations Heat stress is a welfare concern beyond mortality. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) describes behavioral indicators: open-mouthed breathing, drooling, recumbency, and seeking shade. Panting scores (0 to 4) are a validated tool for cattle, scores above 2 for more than two hours indicate action needed. Stocking density must be reduced during hot periods to allow free access to drinking and shade. [Heat stress and goat welfare: Adaptation and production considerations](https://api.elsevier.com/content/abstract/scopus_id/85103491888) (2021) emphasizes that goats exhibit increased agonistic behavior when heat-stressed and overcrowded, leading to injuries. Lame or sick animals cannot compete for water or shade and should be moved to a hospital pen with additional cooling resources. ### Worker and [Food Safety](/knowledge/bacteria/livestock-bacteria/cooking-chicken-bacteria-prevention) Handling livestock during heat stress increases risk of injury to both animals and workers. [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) guidance advises that moving animals should be restricted to the early morning or late evening when ambient temperature is below 30 degrees Celsius. Electric prods should not be used on heat-stressed animals because exertion exacerbates hyperthermia and may cause sudden death. Workers must be rotated frequently and provided with breaks in air-conditioned spaces. Dehydration and heat illness in handlers are common during emergency interventions, a buddy system and mandatory hydration breaks at 30-minute intervals are recommended by [FAO Animal Production and Health](https://www.fao.org/animal-production/en/). Food safety considerations arise from increased risk of carcass contamination during slaughter if animals arrive fatigued. [PubMed record 40942963](https://pubmed.ncbi.nlm.nih.gov/40942963/) links higher fecal shedding of Salmonella in heat-stressed poultry. Pre-slaughter conditioning pens with misting fans and immediate access to water can reduce bacterial shedding. ### Failure Patterns and Practical Monitoring When the plan fails, typical patterns include a lag of 24 to 72 hours between onset of heat stress and morbidity spikes. In swine, respiratory acidosis (open-mouth breathing, reddening of skin, vomiting) progresses to convulsions within hours if not reversed. In poultry, panting intensifies until comb and wattles become cyanotic, followed by prostration. Dairy cattle exhibit sharp drops in milk yield that may persist for days even after temperature returns to normal. The [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) includes disease surveillance protocols that overlap with heat stress monitoring: any cluster of sudden deaths in a herd should prompt immediate environmental review. Practical monitoring combines subjective observations with objective data. A daily walking audit of all pens in the early afternoon (the hottest period) is essential. Signs to note: animals congregating near waterers, heads held low, excessive drooling, or reluctance to move. Use of a simple chart of temperature-humidity index with color-coded action levels allows farm staff to respond without consulting a veterinarian for every decision. However, thresholds for commercial breeds differ from local indigenous stocks, [Genomic responses to climatic challenges in beef cattle: A review](https://api.elsevier.com/content/abstract/scopus_id/85202943555) (2024) notes that Bos indicus breeds tolerate higher temperature-humidity index than Bos taurus. The plan must incorporate breed-specific triggers, typically derived from published literature or extension service recommendations. If no local threshold exists, a conservative approach is to act on a temperature-humidity index of 68 for temperate breeds and 74 for tropically adapted ones, recognizing that these values are approximate and require validation. Records of monitoring and response should be reviewed within one week of each heat event to adjust future actions. This iterative process forms the core of an adaptive plan that improves over time. ## Health Observation and Biosecurity Daily health observation is the principal means of detecting heat stress before it progresses to clinical disease. Stockpersons should inspect all animals at least twice daily during hot weather, paying attention to respiration rate, posture, and willingness to move. Prolonged standing with the head extended, excessive drooling, and open-mouth breathing are consistent indicators of thermoregulatory overload. [Merck Veterinary Manual](https://www.merckvetmanual.com/) emphasizes that reduced feed intake, decreased rumen fill, and a drop in milk yield often precede visible distress by 12 to 24 hours. Rectal temperature measurement, when performed without causing additional stress, provides a direct measure of heat load but must be interpreted in light of ambient conditions and recent handling. The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) recommends integrating these observations into a daily scoring system that can be shared across shifts. Biosecurity measures gain added importance during heat stress because elevated core body temperature and dehydration impair immune function. The [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) notes that stressed animals shed pathogens more readily and are more susceptible to secondary infections. Management must ensure that water sources are not contaminated by manure or standing water, as warm water promotes bacterial growth. Bedding should be kept dry and clean, wet bedding accelerates the growth of opportunistic pathogens. Ventilation systems that draw air through manure storage areas should be redirected away from animal housing to reduce aerosolized pathogen load. The [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) guidance further advises that sick pens be located in cooler, shaded areas and that group size be reduced by 10 to 15 percent during heat events to lower disease transmission risk. ## Diagnostic and Veterinary Escalation When animals display signs incompatible with adaptive thermoregulation, veterinary consultation is indicated. Indications for escalation include rectal temperature exceeding the breed-specific upper limit after 30 minutes of shade and water access, persistent recumbency, inability to stand, or death of more than 2 percent of a group within 24 hours. Diagnostic differentials include acute respiratory infections, electrolyte imbalances, and preexisting cardiac or renal disease that may lower heat tolerance. The [PubMed record 42141240](https://pubmed.ncbi.nlm.nih.gov/42141240/) highlights that postmortem findings in heat-stressed cattle often include pulmonary congestion, petechial hemorrhages, and liver pallor, but these are not pathognomonic and require histopathology for confirmation. [PubMed record 41530826](https://pubmed.ncbi.nlm.nih.gov/41530826/) stresses that antemortem serum biochemistry, particularly elevations in creatine kinase, aspartate aminotransferase, and blood urea nitrogen, can support clinical diagnosis but should not delay management intervention. Veterinarians should be involved in designing the heat stress plan before the season begins, advising on thresholds for emergency actions and reviewing mortality records. [PubMed record 41375413](https://pubmed.ncbi.nlm.nih.gov/41375413/) cautions that treatment protocols for severe heat stress,such as cold water drenching or intravenous fluids,must be tailored to species, age, and pregnancy status to avoid shock or aspiration. In addition, concurrent disease, such as bovine respiratory disease or mastitis, can mimic heat stress signs and may require separate diagnostic workup. The attending veterinarian should also document all cases to refine future trigger thresholds. ## Uncertainty and Sustainability Several sources of uncertainty affect heat stress prediction and response. Individual animal variation in tolerance arises from genetics, coat color, body condition, and prior acclimatization. The [Genomic responses to climatic challenges in beef cattle: A review](https://api.elsevier.com/content/abstract/scopus_id/85202943555) (2024) notes that cattle carrying thermotolerant alleles show lower respiratory rates and better feed efficiency under heat load, but this information is not yet available through on-farm genotyping. Environmental factors such as nighttime cooling, humidity, and wind speed also create nonlinear risk. The [Livestock production system management responses to thermal challenges](https://api.elsevier.com/content/abstract/scopus_id/36448979593) (2007) emphasizes that simple temperature-humidity indices underestimate risk in high solar radiation or low airflow conditions. Producers must therefore allow a safety margin and avoid relying solely on any single forecast metric. Sustainability of heat stress management involves both short-term interventions and long-term system design. The [Simplified climate change adaptation strategies for livestock development in low-and middle-income countries](https://api.elsevier.com/content/abstract/scopus_id/105004451164) (2025) recommends integrating heat-tolerant breeds, improved shade infrastructure, and controlled ventilation into new barn construction. Rotational grazing with access to shaded paddocks reduces cumulative heat load. [The effect of climate change-induced temperature increase on performance and environmental impact of intensive pig production systems](https://api.elsevier.com/content/abstract/scopus_id/85095988324) (2020) shows that mitigation of heat stress reduces mortality and [feed conversion ratio](/knowledge/animal-farming/poultry/feed-conversion-ratio-measuring-improving-poultry-efficiency), lowering the carbon footprint per unit of meat. [Heat stress and goat welfare: Adaptation and production considerations](https://api.elsevier.com/content/abstract/scopus_id/85103491888) (2021) further highlights that goat kids born to heat-stressed dams have lower birth weight and higher neonatal mortality, underscoring the need for year-round maternal management. Sustainability also demands record keeping that captures weather data, animal loss, and intervention outcomes, enabling continuous improvement of the plan. ## Frequently Asked Questions 1. **What clinical signs indicate a livestock animal is experiencing heat stress?** Increased respiratory rate, open-mouth breathing, excessive salivation, recumbency, reduced feed intake, and elevated rectal temperature are common signs. Behavioral changes such as crowding around water sources or seeking shade also signal thermal distress. 2. **How often should I observe animals during a heat event?** At least twice daily, with additional checks during the hottest hours (14:00 to 17:00). Nighttime observation is important because heat load can persist if ambient temperatures do not drop sufficiently. 3. **When should I call a veterinarian for suspected heat stress?** When more than two animals in a group show severe signs (collapse, inability to stand, rectal temperature exceeding breed norms) or when mortality exceeds 2 percent in 24 hours. Also consult if animals do not improve after one hour of cooling and rehydration. 4. **Can heat stress be confused with other diseases?** Yes. Respiratory infections, toxicities, and electrolyte imbalances can produce similar signs. A veterinarian should conduct a differential diagnosis, especially when multiple animals are affected or when the heat stress forecast was not extreme. 5. **Does heat stress increase the risk of disease outbreaks?** Yes. Hyperthermia and dehydration suppress immune function, and stressed animals shed more pathogens. Good hygiene, reduced stocking density, and clean water sources help mitigate secondary disease. 6. **What records should I keep to improve my heat stress plan?** Daily weather data (temperature, humidity, wind speed), animal observation scores, mortality and morbidity numbers, and details of all interventions. These records help refine trigger thresholds over time. 7. **How can I reduce heat stress without costly infrastructure?** Portable shade structures, frequent water changes, adjustment of feeding time to early morning or evening, and moving animals to higher ground or well-ventilated pens are low-cost measures that can yield significant relief. 8. **Is there a genetic component to heat tolerance?** Yes. Bos indicus breeds generally tolerate heat better than Bos taurus breeds, and certain alleles for coat color and hair length confer advantages. Within-breed selection for thermotolerance is an emerging strategy. --- **Educational Veterinary Notice:** This article provides general management principles based on published guidelines and peer-reviewed research. It does not replace a veterinary-client-patient relationship. All thresholds, treatments, and biosecurity measures should be adapted to local conditions, species, and regulatory requirements in consultation with a licensed veterinarian. The authors disclaim liability for any loss or injury resulting from the use of this information. ## Related Farming Guides - [How To Write A Farm Biosecurity Plan](/knowledge/animal-farming/farm-management/how-to-write-a-farm-biosecurity-plan) - [Livestock Farm Record Keeping System](/knowledge/animal-farming/farm-management/livestock-farm-record-keeping-system) - [Livestock Emergency Preparedness Plan](/knowledge/animal-farming/farm-management/livestock-emergency-preparedness-plan) - [Farm Health Intelligence Observation Records Biosecurity Diagnostics And Veterinary Escalation](/knowledge/animal-farming/farm-management/farm-health-intelligence-observation-records-biosecurity-diagnostics-and-veterinary-escalation) - [Animal Welfare Audits Building A Useful Farm Program](/knowledge/animal-farming/farm-management/animal-welfare-audits-building-a-useful-farm-program) ## Related Clinical & Scientific Guides * [Animal Welfare Audits: Building a Useful Farm Program](/knowledge/animal-farming/farm-management/animal-welfare-audits-building-a-useful-farm-program) * [Total Mixed Ration (TMR) for Dairy: Mixing and Feeding Management](/knowledge/animal-farming/farm-management/total-mixed-ration-dairy-mixing-feeding) * [Feed Additives for Livestock: Probiotics, Enzymes, and More](/knowledge/animal-farming/farm-management/feed-additives-livestock-probiotics-enzymes) ## References and Further Reading - [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) - [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) - [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) - [Merck Veterinary Manual](https://www.merckvetmanual.com/) - [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.