Stick to the Formula: A Guide to Deciding If It's Safe to Ride in Hot Weather

Q: What’s the fastest way to cool a hot horse?

Walk in shade, hose–scrape cycles over large muscles, maintain airflow, and offer small sips of cool water.

Q: Is it okay to hose with cold water?

Yes—apply to large muscles and scrape immediately to prevent trapping heat; repeat until breathing eases.

Q: How do I adjust work on high heat-index days?

Shorter sets, more walk breaks, ride during cooler hours, and skip ridden work if the heat index exceeds about 105.

April 9, 2019

Too Hot to Ride? Heat Index, Signs of Overheating, and a Safe Summer Game Plan

By Jon Conklin • Updated August 9, 2025 • 7–9 min read

Heat gets western fast. Instead of guessing, use a heat-index formula, read the early signs, and run a calm, repeatable cool-down. Same horse, better outcomes—because pros stick to a plan when the thermometer climbs.

The Heat Index: A Simple Rider’s Formula

Pair air temperature (°F) with relative humidity (%). When both are high, the body can’t dump heat well.

Green Light: HI under ~90 → Normal flatwork with water breaks.
Yellow: HI ~90–100 → Shorten sets, add walk intervals, ride early/late.
Orange: HI ~100–105 → Keep it very light or hand-walk/longe briefly; prioritize shade and airflow.
Red: HI >105 → Skip ridden work. Hand-walk at most; focus on hydration and cooling.

Quick check without a chart: If temp (°F) + humidity (%) exceeds ~150 and humidity is over 60%, treat it like orange/red—heat sheds poorly.

When to Scale or Skip

Shorten warm-ups; favor walk breaks and shade.
Swap schooling jumps for rails/poles; keep intensity bursts brief.
Ride at dawn/late evening; avoid peak sun and dead-air arenas.
Postpone if the horse is older, unfit, dark-coated, or not acclimated.

Early Warning Signs of Overheating

Elevated breathing that doesn’t settle within a few minutes of walking.
Excessive sweating or, worse, stops sweating (red flag).
Glassy eyes, lethargy, uncoordinated steps, louder heartbeat at rest.
Skin pinch stays tented, gums tacky or dark.

Emergency: If the horse seems dull, wobbly, or not sweating in heat—start active cooling (see below) and call your veterinarian.

Fast, Safe Cool-Down Protocol

1) Walk & water

Hand-walk in shade with small sips of cool (not ice-cold) water. Loosen tack to improve air flow.

2) Hose–scrape cycles

Hose large muscle groups (neck, shoulders, flank, hindquarters), scrape immediately, repeat until breathing eases.

3) Air movement

Use safe barn fans to move air across the body—not into eyes/nostrils. Gentle breeze is the goal.

4) Post-work support

After the horse is cool and dry, apply sensation-free support to high-motion zones as needed and allow quiet stall time.

Barn Routine for Heat Waves

Schedule hay, grain, and rides for cooler hours; keep timing consistent.
Electrolytes per label guidance for working horses; free-choice clean water and salt.
Shade + airflow in stalls and tack areas; avoid dead-air corners.
Monitor recovery: count respirations/heart rate post-ride and log trends.

Note: This is general guidance; always follow your veterinarian’s advice for your horse, discipline, and climate.